51
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Preston D, Sutton JJ, Gordon KC, Crowley JD. A Nona‐nuclear Heterometallic Pd
3
Pt
6
“Donut”‐Shaped Cage: Molecular Recognition and Photocatalysis. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201804745] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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52
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Preston D, Sutton JJ, Gordon KC, Crowley JD. A Nona-nuclear Heterometallic Pd 3 Pt 6 "Donut"-Shaped Cage: Molecular Recognition and Photocatalysis. Angew Chem Int Ed Engl 2018; 57:8659-8663. [PMID: 29774643 DOI: 10.1002/anie.201804745] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Indexed: 11/10/2022]
Abstract
We report a simple, low-symmetry 2-(1-(pyridine-4-methyl)-1H-1,2,3-triazol-4-yl)pyridine ligand that has both monodentate and bidentate binding sites. With platinum(II) and/or palladium(II) ions, two examples of a new nona-nuclear metallo-assembly have been accessed. These complexes were characterized by NMR spectroscopy, electrospray mass spectrometry (ESI-MS), and in key cases, X-ray crystallography. The cages possess three clefts comprised of planar cationic panels. This structural feature enables the binding of planar aromatic guests such as anthracene. More interestingly, the heterometallic assembly was able to catalyze the light-induced [4+2] cycloaddition of anthracene with singlet oxygen.
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53
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Shillito GE, Hall TBJ, Preston D, Traber P, Wu L, Reynolds KEA, Horvath R, Sun XZ, Lucas NT, Crowley JD, George MW, Kupfer S, Gordon KC. Dramatic Alteration of 3ILCT Lifetimes Using Ancillary Ligands in [Re(L)(CO) 3(phen-TPA)] n+ Complexes: An Integrated Spectroscopic and Theoretical Study. J Am Chem Soc 2018. [PMID: 29537264 DOI: 10.1021/jacs.7b12868] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The ground and excited state photophysical properties of a series of fac-[Re(L)(CO)3(α-diimine)] n+ complexes, where L = Br-, Cl-, 4-dimethylaminopyridine (dmap) and pyridine (py) have been extensively studied utilizing numerous electronic and vibrational spectroscopic techniques in conjunction with a suite of quantum chemical methods. The α-diimine ligand consists of 1,10-phenanthroline with the highly electron donating triphenylamine (TPA) appended in the 5 position. This gives rise to intraligand charge transfer (ILCT) states lying lower in energy than the conventional metal-to-ligand charge transfer (MLCT) state, the energies of which are red and blue-shifted, respectively, as the ancillary ligand, L becomes more electron withdrawing. The emitting state is 3ILCT in nature for all complexes studied, characterized through transient absorption and emission, transient resonance Raman (TR2), time-resolved infrared (TRIR) spectroscopy and TDDFT calculations. Systematic modulation of the ancillary ligand causes unanticipated variation in the 3ILCT lifetime by 2 orders of magnitude, ranging from 6.0 μs for L = Br- to 27 ns for L = py, without altering the nature of the excited state formed or the relative order of the other CT states present. Temperature dependent lifetime measurements and quantum chemical calculations provide no clear indication of close lying deactivating states, MO switching, contributions from a halide-to-ligand charge transfer (XLCT) state or dramatic changes in spin-orbit coupling. It appears that the influence of the ancillary ligand on the excited state lifetime could be explained in terms of energy gap law, in which there is a correlation between ln( knr) and Eem with a slope of -21.4 eV-1 for the 3ILCT emission.
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54
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Findlay JA, McAdam CJ, Sutton JJ, Preston D, Gordon KC, Crowley JD. Metallosupramolecular Architectures Formed with Ferrocene-Linked Bis-Bidentate Ligands: Synthesis, Structures, and Electrochemical Studies. Inorg Chem 2018; 57:3602-3614. [PMID: 29381330 DOI: 10.1021/acs.inorgchem.7b02503] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The self-assembly of ligands of different geometries with metal ions gives rise to metallosupramolecular architectures of differing structural types. The rotational flexibility of ferrocene allows for conformational diversity, and, as such, self-assembly processes with 1,1'-disubstituted ferrocene ligands could lead to a variety of interesting architectures. Herein, we report a small family of three bis-bidentate 1,1'-disubstituted ferrocene ligands, functionalized with either 2,2'-bipyridine or 2-pyridyl-1,2,3-triazole chelating units. The self-assembly of these ligands with the (usually) four-coordinate, diamagnetic metal ions Cu(I), Ag(I), and Pd(II) was examined using a range of techniques including 1H and DOSY NMR spectroscopies, high-resolution electrospray ionization mass spectrometry, X-ray crystallography, and density functional theory calculations. Additionally, the electrochemical properties of these redox-active metallosupramolecular assemblies were examined using cyclic voltammetry and differential pulse voltammetry. The copper(I) complexes of the 1,1'-disubstituted ferrocene ligands were found to be coordination polymers, while the silver(I) and palladium(II) complexes formed discrete [1 + 1] or [2 + 2] metallomacrocyclic architectures.
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55
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van Hilst QVC, Lagesse NR, Preston D, Crowley JD. Functional metal complexes from CuAAC “click” bidentate and tridentate pyridyl-1,2,3-triazole ligands. Dalton Trans 2018; 47:997-1002. [DOI: 10.1039/c7dt04570k] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
This Frontiers article examines the use of “click” complexes for the development of catalysts, anti-cancer and anti-bacterial agents and emissive materials.
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56
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Findlay JA, Crowley JD. Functional nanomachines: Recent advances in synthetic molecular machinery. Tetrahedron Lett 2018. [DOI: 10.1016/j.tetlet.2017.12.036] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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57
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Ross DAW, Preston D, Crowley JD. Self-Assembly with 2,6-Bis(1-(pyridin-4-ylmethyl)-1H-1,2,3-triazol-4-yl)pyridine: Silver(I) and Iron(II) Complexes. Molecules 2017; 22:E1762. [PMID: 29048381 PMCID: PMC6151823 DOI: 10.3390/molecules22101762] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 10/14/2017] [Accepted: 10/14/2017] [Indexed: 12/17/2022] Open
Abstract
A new "click" ligand, 2,6-bis(1-(pyridin-4-ylmethyl)-1H-1,2,3-triazol-4-yl)pyridine (L) featuring a tridentate 2,6-bis(1,2,3-triazol-4-yl)pyridine (tripy) pocket and two pyridyl (py) units was synthesized in modest yield (42%) using the copper(I) catalyzed azide-alkyne cycloaddition (CuAAC) reaction. The coordination chemistry of the ligand with silver(I) and iron(II) ions was examined using a battery of solution (¹H and DOSY (diffusion ordered spectroscopy) nuclear magnetic resonance (NMR), infrared and absorption spectroscopies, high-resolution electrospray ionization mass spectrometry (HR-ESI-MS)), and solid state (X-ray crystallography, elemental analysis) techniques. When treated with silver(I) ions, the ligand forms discrete [Ag(L)]⁺ (X-, where X- = BF₄-, NO₃- or SbF₆-) complexes in dimethyl sulfoxide (DMSO) solution but these complexes crystallize as coordination polymers. The addition of [Fe(H₂O)₆](BF₄)₂ to an acetonitrile solution of the ligand forms the expected monomeric octahedral [Fe(L)₂]2+ complex and treatment of the iron(II) complex with AgBF₄ generates a heterometallic linear coordination polymer.
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58
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Kim TY, Digal L, Gardiner MG, Lucas NT, Crowley JD. Octahedral [Pd6
L8
]12+
Metallosupramolecular Cages: Synthesis, Structures and Guest-Encapsulation Studies. Chemistry 2017; 23:15089-15097. [DOI: 10.1002/chem.201702518] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 08/17/2017] [Indexed: 01/09/2023]
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59
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Vasdev RAS, Preston D, Crowley JD. Multicavity Metallosupramolecular Architectures. Chem Asian J 2017; 12:2513-2523. [PMID: 28755432 DOI: 10.1002/asia.201700948] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Indexed: 12/22/2022]
Abstract
Discrete metallosupramolecular systems are often macrocyclic or cage-like architectures with an accessible internal cavity. Guest molecules can reside within these cavities and much of the interest in these systems is derived from these fascinating host-guest interactions. A range of potential applications stem from the ability of these metallosupramolecular architectures to encapsulate guests. These applications include catalysis or acting as molecular reaction flasks, the molecular scavenging of pollutants, storage of reactive species, and drug delivery. Multicavity metallosupramolecular architectures combine the ability of large hollow assemblies to bind multiple guests concurrently with the binding specificity associated with small cages. A variety of different approaches to generating separate compartments within a single metallosupramolecular assembly have emerged. These include interpenetrated cages, cages with polytopic ligands that have a long backbone, and molecules that have two or more clefts. This review examines these approaches, and highlights key contributions to the field.
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60
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Preston D, White KF, Lewis JEM, Vasdev RAS, Abrahams BF, Crowley JD. Solid-State Gas Adsorption Studies with Discrete Palladium(II) [Pd 2 (L) 4 ] 4+ Cages. Chemistry 2017; 23:10559-10567. [PMID: 28508442 DOI: 10.1002/chem.201701477] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Indexed: 01/03/2023]
Abstract
The need for effective CO2 capture systems remains high, and due to their tunability, metallosupramolecular architectures are an attractive option for gas sorption. While the use of extended metal organic frameworks for gas adsorption has been extensively explored, the exploitation of discrete metallocage architectures to bind gases remains in its infancy. Herein the solid state gas adsorption properties of a series of [Pd2 (L)4 ]4+ lantern shaped coordination cages (L = variants of 2,6-bis(pyridin-3-ylethynyl)pyridine), which had solvent accessible internal cavities suitable for gas binding, have been investigated. The cages showed little interaction with dinitrogen gas but were able to take up CO2 . The best performing cage reversibly sorbed 1.4 mol CO2 per mol cage at 298 K, and 2.3 mol CO2 per mol cage at 258 K (1 bar). The enthalpy of binding was calculated to be 25-35 kJ mol-1 , across the number of equivalents bound, while DFT calculations on the CO2 binding in the cage gave ΔE for the cage-CO2 interaction of 23-28 kJ mol-1 , across the same range. DFT modelling suggested that the binding mode is a hydrogen bond between the carbonyl oxygen of CO2 and the internally directed hydrogen atoms of the cage.
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61
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Preston D, White KF, Lewis JEM, Vasdev RAS, Abrahams BF, Crowley JD. Inside Back Cover: Solid-State Gas Adsorption Studies with Discrete Palladium(II) [Pd2
(L)4
]4+
Cages (Chem. Eur. J. 44/2017). Chemistry 2017. [DOI: 10.1002/chem.201702639] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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62
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Preston D, Lewis JEM, Crowley JD. Multicavity [PdnL4]2n+ Cages with Controlled Segregated Binding of Different Guests. J Am Chem Soc 2017; 139:2379-2386. [DOI: 10.1021/jacs.6b11982] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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63
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Vasdev RAS, Preston D, Crowley JD. Functional metallosupramolecular architectures using 1,2,3-triazole ligands: it's as easy as 1,2,3 “click”. Dalton Trans 2017; 46:2402-2414. [DOI: 10.1039/c6dt04702e] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Self-assembled metallosupramolecular architectures generated using “click” ligands have become an increasingly popular area of inorganic chemistry.
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64
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Scottwell SØ, Barnsley JE, McAdam CJ, Gordon KC, Crowley JD. A ferrocene based switchable molecular folding ruler. Chem Commun (Camb) 2017. [DOI: 10.1039/c7cc03358c] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A bis(ferrocene) three tiered molecular folding ruler can be induced to undergo a large scale extension and contraction process using either chemical or better electrochemical methods.
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65
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Vasdev RAS, Preston D, Scottwell SØ, Brooks HJL, Crowley JD, Schramm MP. Oxidatively Locked [Co₂L₃] 6+ Cylinders Derived from Bis(bidentate) 2-Pyridyl-1,2,3-triazole "Click" Ligands: Synthesis, Stability, and Antimicrobial Studies. Molecules 2016; 21:E1548. [PMID: 27854348 PMCID: PMC6273053 DOI: 10.3390/molecules21111548] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 11/04/2016] [Accepted: 11/10/2016] [Indexed: 11/17/2022] Open
Abstract
A small family of [Co₂(Lpytrz)₃]6+ cylinders was synthesised from bis(bidentate) 2-pyridyl-1,2,3-triazole "click" ligands (Lpytrz) through an "assembly-followed-by-oxidation" method. The cylinders were characterised using ¹H, 13C, and DOSY NMR, IR, and UV-Vis spectroscopies, along with electrospray ionisation mass spectrometry (ESMS). Stability studies were conducted in dimethyl sulfoxide (DMSO) and D₂O. In contrast to similar, previously studied, [Fe₂(Lpytrz)₃]4+ helicates the more kinetically inert [Co₂(Lpytrz)₃]6+ systems proved stable (over a period of days) when exposed to DMSO and were even more stable in D₂O. The triply stranded [Co₂(Lpytrz)₃]6+ systems and the corresponding "free" ligands were tested for antimicrobial activity in vitro against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) microorganisms. Agar-based disk diffusion and Mueller-Hinton broth micro-dilution assays showed that the [Co₂(Lpytrz)₃]6+ cylinders were not active against either strain of bacteria. It is presumed that a high charge of the [Co₂(Lpytrz)₃]6+ cylinders is preventing them from crossing the bacterial cell membranes, rendering the compounds biologically inactive.
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66
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Huff GS, Lo WKC, Horvath R, Turner JO, Sun XZ, Weal GR, Davidson HJ, Kennedy ADW, McAdam CJ, Crowley JD, George MW, Gordon KC. Excited States of Triphenylamine-Substituted 2-Pyridyl-1,2,3-triazole Complexes. Inorg Chem 2016; 55:12238-12253. [DOI: 10.1021/acs.inorgchem.6b01959] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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67
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Kumar SV, Scottwell SØ, Waugh E, McAdam CJ, Hanton LR, Brooks HJL, Crowley JD. Antimicrobial Properties of Tris(homoleptic) Ruthenium(II) 2-Pyridyl-1,2,3-triazole “Click” Complexes against Pathogenic Bacteria, Including Methicillin-Resistant Staphylococcus aureus (MRSA). Inorg Chem 2016; 55:9767-9777. [DOI: 10.1021/acs.inorgchem.6b01574] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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68
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Preston D, Tucker RAJ, Garden AL, Crowley JD. Heterometallic [MnPtn(L)2n]x+ Macrocycles from Dichloromethane-Derived Bis-2-pyridyl-1,2,3-triazole Ligands. Inorg Chem 2016; 55:8928-34. [DOI: 10.1021/acs.inorgchem.6b01435] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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69
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Preston D, Barnsley JE, Gordon KC, Crowley JD. Controlled Formation of Heteroleptic [Pd2(La)2(Lb)2]4+ Cages. J Am Chem Soc 2016; 138:10578-85. [DOI: 10.1021/jacs.6b05629] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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70
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Barnsley JE, Scottwell SØ, Elliott ABS, Gordon KC, Crowley JD. Structural, Electronic, and Computational Studies of Heteroleptic Cu(I) Complexes of 6,6′-Dimesityl-2,2′-bipyridine with Ferrocene-Appended Ethynyl-2,2′-bipyridine Ligands. Inorg Chem 2016; 55:8184-92. [DOI: 10.1021/acs.inorgchem.6b01300] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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71
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McKay AP, Lo WK, Preston D, Giles GI, Crowley JD, Barnsley JE, Gordon KC, McMorran DA. Palladium(II) and platinum(II) complexes of ((2-pyridyl)pyrazol-1-ylmethyl)benzoic acids: Synthesis, Solid state characterisation and biological cytotoxicity. Inorganica Chim Acta 2016. [DOI: 10.1016/j.ica.2016.02.038] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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72
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Lo WKC, Castillo CE, Gueret R, Fortage J, Rebarz M, Sliwa M, Thomas F, McAdam CJ, Jameson GB, McMorran DA, Crowley JD, Collomb MN, Blackman AG. Synthesis, Characterization, and Photocatalytic H2-Evolving Activity of a Family of [Co(N4Py)(X)](n+) Complexes in Aqueous Solution. Inorg Chem 2016; 55:4564-81. [PMID: 27064169 DOI: 10.1021/acs.inorgchem.6b00391] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of [Co(III)(N4Py)(X)](ClO4)n (X = Cl(-), Br(-), OH(-), N3(-), NCS(-)-κN, n = 2: X = OH2, NCMe, DMSO-κO, n = 3) complexes containing the tetrapyridyl N5 ligand N4Py (N4Py = 1,1-di(pyridin-2-yl)-N,N-bis(pyridin-2-ylmethyl)methanamine) has been prepared and fully characterized by infrared (IR), UV-visible, and NMR spectroscopies, high-resolution electrospray ionization mass spectrometry (HRESI-MS), elemental analysis, X-ray crystallography, and electrochemistry. The reduced Co(II) and Co(I) species of these complexes have been also generated by bulk electrolyses in MeCN and characterized by UV-visible and EPR spectroscopies. All tested complexes are catalysts for the photocatalytic production of H2 from water at pH 4.0 in the presence of ascorbic acid/ascorbate, using [Ru(bpy)3](2+) as a photosensitizer, and all display similar H2-evolving activities. Detailed mechanistic studies show that while the complexes retain the monodentate X ligand upon electrochemical reduction to Co(II) species in MeCN solution, in aqueous solution, upon reduction by ascorbate (photocatalytic conditions), [Co(II)(N4Py)(HA)](+) is formed in all cases and is the precursor to the Co(I) species which presumably reacts with a proton. These results are in accordance with the fact that the H2-evolving activity does not depend on the chemical nature of the monodentate ligand and differ from those previously reported for similar complexes. The catalytic activity of this series of complexes in terms of turnover number versus catalyst (TONCat) was also found to be dependent on the catalyst concentration, with the highest value of 230 TONCat at 5 × 10(-6) M. As revealed by nanosecond transient absorption spectroscopy measurements, the first electron-transfer steps of the photocatalytic mechanism involve a reductive quenching of the excited state of [Ru(bpy)3](2+) by ascorbate followed by an electron transfer from [Ru(II)(bpy)2(bpy(•-))](+) to the [Co(II)(N4Py)(HA)](+) catalyst. The reduced catalyst then enters into the H2-evolution cycle.
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73
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Elliott ABS, Lewis JEM, van der Salm H, McAdam CJ, Crowley JD, Gordon KC. Luminescent Cages: Pendant Emissive Units on [Pd2L4]4+ “Click” Cages. Inorg Chem 2016; 55:3440-7. [DOI: 10.1021/acs.inorgchem.5b02843] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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74
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Scottwell SØ, Crowley JD. Ferrocene-containing non-interlocked molecular machines. Chem Commun (Camb) 2016; 52:2451-64. [DOI: 10.1039/c5cc09569g] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Ferrocene is chemically robust and readily functionalized which enables its facile incorporation into more complex molecular systems. This coupled with ferrocene's reversible redox properties and ability to function as a “molecular ball bearing” has led to the use of ferrocene as a component in wide range of non-interlocked synthetic molecular machine systems.
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75
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Kumar SV, Lo WKC, Brooks HJL, Hanton LR, Crowley JD. Antimicrobial Properties of Mono- and Di-fac-rhenium Tricarbonyl 2-Pyridyl-1,2,3-triazole Complexes. Aust J Chem 2016. [DOI: 10.1071/ch15433] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A family of mono- and di-fac-rhenium tricarbonyl 2-pyridyl-1,2,3-triazole complexes with different aliphatic and aromatic substituents was synthesized in good-to-excellent yields (46–99 %). The complexes were characterized by 1H and 13C NMR spectroscopy, infrared spectroscopy, electronic (UV-visible) spectroscopy, high-resolution electrospray mass spectrometry, and elemental analyses. In four examples, the solid-state structures of the rhenium(i) complexes were confirmed by X-ray crystallography. The family of the mono- and di-rhenium(i) complexes and the corresponding 2-pyridyl-1,2,3-triazole was tested for antimicrobial activity in vitro against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) microorganisms. Agar-based disk diffusion assays indicated that most of the rhenium(i) complexes were active against Staphylococcus aureus and that the cationic rhenium(i) complexes were more active than the related neutral systems. However, in all cases, the minimum inhibitory concentrations for all the complexes were modest (i.e. 16–1024 µg mL–1).
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76
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77
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Preston D, McNeill SM, Lewis JEM, Giles GI, Crowley JD. Enhanced kinetic stability of [Pd2L4]4+ cages through ligand substitution. Dalton Trans 2016; 45:8050-60. [DOI: 10.1039/c6dt00133e] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
[Pd2(tripy)4]4+ cage architectures (where tripy = 2,6-bis(pyridin-3-ylethynyl)pyridine) were made more kinetically robust in the presence of range of nucleophiles by the addition of amino groups in either the 2-(2A-tripy) or 3-(3A-tripy) positions of the tripy ligands' terminal pyridines, with the [Pd2(2A-tripy)4]4+ cage proving the most stable.
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78
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Wright JR, Crowley JD, Lucas NT. Carbon-rich “Click” 1,2,3-triazoles: hexaphenylbenzene and hexa-peri-hexabenzocoronene-based ligands for Suzuki–Miyaura catalysts. Chem Commun (Camb) 2016; 52:12976-12979. [DOI: 10.1039/c6cc07413h] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Routes to polyaromatic 1,2,3-triazole ligands have been developed, their [PdCl2L2] complexes characterised and assessed as precatalysts in the Suzuki–Miyaura reaction.
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79
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Kim TY, Lucas NT, Crowley JD. A diaryl-linked [Pd2L4]4+ metallosupramolecular architecture: synthesis, structures and cisplatin binding studies. Supramol Chem 2015. [DOI: 10.1080/10610278.2015.1063633] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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80
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Lo WKC, Huff GS, Preston D, McMorran DA, Giles GI, Gordon KC, Crowley JD. A Dinuclear Platinum(II) N4Py Complex: An Unexpected Coordination Mode For N4Py. Inorg Chem 2015; 54:6671-3. [DOI: 10.1021/acs.inorgchem.5b01032] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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81
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McNeill SM, Preston D, Lewis JEM, Robert A, Knerr-Rupp K, Graham DO, Wright JR, Giles GI, Crowley JD. Biologically active [Pd2L4](4+) quadruply-stranded helicates: stability and cytotoxicity. Dalton Trans 2015; 44:11129-36. [PMID: 25997516 DOI: 10.1039/c5dt01259g] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
There is emerging interest in the anti-proliferative effects of metallosupramolecular systems due to the different size and shape of these metallo-architectures compared to traditional small molecule drugs. Palladium(II)-containing systems are the most abundant class of metallosupramolecular complexes, yet their biological activity has hardly been examined. Here a small series of [Pd2(L)4](BF4)4 quadruply-stranded, dipalladium(II) architectures were screened for their cytotoxic effects against three cancer cell lines and one non-malignant line. The helicates exhibited a range of cytotoxic properties, with the most cytotoxic complex [Pd2(hextrz)4](BF4)4 possessing low micromolar IC50 values against all of the cell lines tested, while the other helicates displayed moderate or no cytotoxicity. Against the MDA-MB-231 cell line, which is resistant to platinum-based drugs, [Pd2(hextrz)4](BF4)4 was 7-fold more active than cisplatin. Preliminary mechanistic studies indicate that the [Pd2(hextrz)4](BF4)4 helicate does not induce cell death in the same way as clinically used metal complexes such as cisplatin. Rather than interacting with DNA, the helicate appears to disrupt the cell membrane. These studies represent the first biological characterisation of quadruply-stranded helicate architectures, and provide insight into the design requirements for the development of biologically active and stable palladium(II)-containing metallosupramolecular architectures.
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82
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Noor A, Maloney DL, Lewis JEM, Lo WKC, Crowley JD. Inside Cover: Acid-Base Driven Ligand Exchange with Palladium(II) “Click” Complexes (Asian J. Org. Chem. 3/2015). ASIAN J ORG CHEM 2015. [DOI: 10.1002/ajoc.201590005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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83
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Lo WK, McAdam CJ, Blackman AG, Crowley JD, McMorran DA. The pentadentate ligands 2PyN2Q and N4Py, and their Cu(II) and Zn(II) complexes: A synthetic, spectroscopic and crystallographic structural study. Inorganica Chim Acta 2015. [DOI: 10.1016/j.ica.2014.11.036] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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84
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Lo WKC, Huff GS, Cubanski JR, Kennedy ADW, McAdam CJ, McMorran DA, Gordon KC, Crowley JD. Comparison of inverse and regular 2-pyridyl-1,2,3-triazole "click" complexes: structures, stability, electrochemical, and photophysical properties. Inorg Chem 2015; 54:1572-87. [PMID: 25615621 DOI: 10.1021/ic502557w] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Two inverse 2-pyridyl-1,2,3-triazole "click" ligands, 2-(4-phenyl-1H-1,2,3-triazol-1-yl)pyridine and 2-(4-benzyl-1H-1,2,3-triazol-1-yl)pyridine, and their palladium(II), platinum(II), rhenium(I), and ruthenium(II) complexes have been synthesized in good to excellent yields. The properties of these inverse "click" complexes have been compared to the isomeric regular compounds using a variety of techniques. X-ray crystallographic analysis shows that the regular and inverse complexes are structurally very similar. However, the chemical and physical properties of the isomers are quite different. Ligand exchange studies and density functional theory (DFT) calculations indicate that metal complexes of the regular 2-(1-R-1H-1,2,3-triazol-4-yl)pyridine (R = phenyl, benzyl) ligands are more stable than those formed with the inverse 2-(4-R-1H-1,2,3-triazol-1-yl)pyridine (R = phenyl, benzyl) "click" chelators. Additionally, the bis-2,2'-bipyridine (bpy) ruthenium(II) complexes of the "click" chelators have been shown to have short excited state lifetimes, which in the inverse triazole case, resulted in ejection of the 2-pyridyl-1,2,3-triazole ligand from the complex. Under identical conditions, the isomeric regular 2-pyridyl-1,2,3-triazole ruthenium(II) bpy complexes are photochemically inert. The absorption spectra of the inverse rhenium(I) and platinum(II) complexes are red-shifted compared to the regular compounds. It is shown that conjugation between the substituent group R and triazolyl unit has a negligible effect on the photophysical properties of the complexes. The inverse rhenium(I) complexes have large Stokes shifts, long metal-to-ligand charge transfer (MLCT) excited state lifetimes, and respectable quantum yields which are relatively solvent insensitive.
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85
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Preston D, Fox-Charles A, Lo WKC, Crowley JD. Chloride triggered reversible switching from a metallosupramolecular [Pd2L4]4+ cage to a [Pd2L2Cl4] metallo-macrocycle with release of endo- and exo-hedrally bound guests. Chem Commun (Camb) 2015; 51:9042-5. [DOI: 10.1039/c5cc02226f] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
A metallosupramolecular [Pd2L4]4+ cage can be cleanly, and reversibly, converted into a [Pd2L2Cl4] metallo-macrocycle upon addition or removal of chloride ions.
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86
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Cubanski JR, Reish ME, Blackman AG, Steel PJ, Gordon KC, McMorran DA, Crowley JD. Hybrid Pyrazolyl-1,2,3-Triazolyl Tripodal Tetraamine Ligands: Click Synthesis and Cobalt(III) Complexes. Aust J Chem 2015. [DOI: 10.1071/ch14700] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
A family of tripodal tetraamine ligands incorporating two pyrazolyl and one 1,2,3-triazolyl donor arm have been synthesized in modest-to-excellent yields (42–90 %) using the copper(i)-catalyzed azide–alkyne cycloaddition (CuAAC) reaction. Mono-, bis-, and tris-tripodal ligand scaffolds were readily generated using this method. The coordination chemistry of the ligands with cobalt(iii) ions has been studied, and cobalt(iii) carbonato complexes of the ligands have been isolated and characterized spectroscopically and crystallographically. X-ray crystallography and NMR spectroscopy of the mono-metallic complexes showed that racemic mixtures of the cis-isomer are formed selectively. The di- and tri-metallic systems could not be crystallized, but NMR spectroscopy indicates that these compounds were isolated as mixtures of stereoisomers.
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87
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Scottwell SØ, Elliott ABS, Shaffer KJ, Nafady A, McAdam CJ, Gordon KC, Crowley JD. Chemically and electrochemically induced expansion and contraction of a ferrocene rotor. Chem Commun (Camb) 2015; 51:8161-4. [DOI: 10.1039/c5cc01973g] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A 2,2′-bipyridine-appended ferrocene rotor can be switched, upon treatment with [Cu(CH3CN)4](PF6) and 6,6′-dimesityl-2,2′-bipyridine, from the stacked (syn) conformation to the unstacked (anti) conformation. The switching was completely reversible and could be triggered either chemically, or electrochemically.
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88
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Noor A, Maloney DL, Lewis JEM, Lo WKC, Crowley JD. Acid-Base Driven Ligand Exchange with Palladium(II) “Click” Complexes. ASIAN J ORG CHEM 2014. [DOI: 10.1002/ajoc.201402197] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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89
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Noor A, Huff GS, Kumar SV, Lewis JEM, Paterson BM, Schieber C, Donnelly PS, Brooks HJL, Gordon KC, Moratti SC, Crowley JD. [Re(CO)3]+ Complexes of exo-Functionalized Tridentate “Click” Macrocycles: Synthesis, Stability, Photophysical Properties, Bioconjugation, and Antibacterial Activity. Organometallics 2014. [DOI: 10.1021/om500664v] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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90
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Noor A, Lo WKC, Moratti SC, Crowley JD. CuAAC "click" active-template synthesis of functionalised [2]rotaxanes using small exo-substituted macrocycles: how small is too small? Chem Commun (Camb) 2014; 50:7044-7. [PMID: 24850165 DOI: 10.1039/c4cc03077j] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two "small" 22- and 24-membered exo-alcohol functionalised pyridyl macrocycles are exploited in the CuAAC active-template synthesis of [2]rotaxanes. The 24-membered macrocycle forms [2]rotaxanes in good yields while the smaller 22-membered macrocycle does not lead to interlocked products.
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91
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Lo WKC, Cavigliasso G, Stranger R, Crowley JD, Blackman AG. Five-Coordinate [PtII(bipyridine)2(phosphine)]n+ Complexes: Long-Lived Intermediates in Ligand Substitution Reactions of [Pt(bipyridine)2]2+ with Phosphine Ligands. Inorg Chem 2014; 53:3595-605. [DOI: 10.1021/ic403089j] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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92
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Lewis JEM, Elliott ABS, McAdam CJ, Gordon KC, Crowley JD. ‘Click’ to functionalise: synthesis, characterisation and enhancement of the physical properties of a series of exo- and endo-functionalised Pd2L4nanocages. Chem Sci 2014. [DOI: 10.1039/c4sc00434e] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Facile CuAAC ‘click’ chemistry has been utilised toexo-functionalise Pd2L4host nanocages with electrochemically active, emissive and solubilising groups.
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93
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Noor A, Moratti SC, Crowley JD. Active-template synthesis of “click” [2]rotaxane ligands: self-assembly of mechanically interlocked metallo-supramolecular dimers, macrocycles and oligomers. Chem Sci 2014. [DOI: 10.1039/c4sc01438c] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A "click" active-metal-template strategy has been exploited to develop mono- and bi-2,2′,6′,2″-terpyridine functionalised [2]rotaxanes. When reacted with Fe(ii) ions these rotaxanes formed metallo-bis-([2]rotaxanes), macrocycles and oligomers.
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94
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Wright J, Young PC, Lucas N, Lee AL, Crowley JD. Gold(I) and Palladium(II) Complexes of 1,3,4-Trisubstituted 1,2,3-Triazol-5-ylidene "Click" Carbenes: Systematic Study of the Electronic and Steric Influence on Catalytic Activity. Organometallics 2013; 32:7065-7076. [PMID: 24353365 PMCID: PMC3862405 DOI: 10.1021/om400773n] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Indexed: 02/06/2023]
Abstract
The synthesis of a small family of six electronically and sterically modified 1,3,4-trisubstituted 1,2,3-triazol-5-ylidene gold(I) chloride complexes is described. Additionally, the corresponding trans-[PdBr2(iPr2-bimy)(1,3,4-trisubstituted 1,2,3-triazol-5-ylidene)] complexes are also generated and used to examine the donor strength of the 1,3,4-trisubstituted 1,2,3-triazol-5-ylidene ligands. All compounds have been characterized by 1H and 13C NMR and IR spectroscopy, high-resolution electrospray mass spectrometry (HR-ESI-MS), and elemental analysis. The molecular structures of four of the gold(I) and four of the palladium(II) complexes were determined using X-ray crystallography. Finally, it is demonstrated that these 1,2,3-triazol-5-ylidene gold(I) chloride complexes (Au(trz)Cl) are able to catalyze the cycloisomerization of 1,6-enynes, in high yield and regioselectivity, as well as the intermolecular direct etherification of allylic alcohols. Exploiting the Au(trz)Cl precatalysts allowed the etherification of allylic alcohols to be carried out under milder conditions, with better yield and regioselectivity than selected commercially available gold(I) catalysts.
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95
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Lewis JE, Crowley JD. Exo- and endo-hedral interactions of counteranions with tetracationic Pd2L4 metallosupramolecular architectures. Supramol Chem 2013. [DOI: 10.1080/10610278.2013.842644] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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96
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Cavigliasso G, Stranger R, Lo WK, Crowley JD, Blackman AG. The nature of species derived from [Pt(bipy)2]2+ in aqueous solution: X-ray structural, mass spectral, NMR, and computational studies. Polyhedron 2013. [DOI: 10.1016/j.poly.2013.05.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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97
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Anderson CB, Elliott ABS, Lewis JEM, McAdam CJ, Gordon KC, Crowley JD. fac-Re(CO)3 complexes of 2,6-bis(4-substituted-1,2,3-triazol-1-ylmethyl)pyridine "click" ligands: synthesis, characterisation and photophysical properties. Dalton Trans 2013; 41:14625-32. [PMID: 23104300 DOI: 10.1039/c2dt31569f] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The syntheses of the 4-n-propyl and 4-phenyl substituted fac-Re(CO)(3) complexes of the tridentate "click" ligand (2,6-bis(4-substituted-1,2,3-triazol-1-ylmethyl)pyridine) are described. The complexes were obtained by refluxing methanol solutions of [Re(CO)(5)Cl], AgPF(6) and either the 4-propyl or 4-phenyl substituted ligand for 16 h. The ligands and the two rhenium(I) complexes were characterised by elemental analysis, HR-ESMS, ATR-IR, (1)H and (13)C NMR spectroscopy and the molecular structures of both complexes were confirmed by X-ray crystallography. The electronic structure of the fac-Re(CO)(3) "click" complexes was probed using UV-Vis, Raman and emission spectroscopy, cyclic voltammetry and DFT calculations. Altering the electronic nature of the ligand's substituent, from aromatic to alkyl, had little effect on the absorption/emission maxima and electrochemical properties of the complexes indicating that the 1,2,3-triazole unit may insulate the metal centre from the electronic modification at the ligands' periphery. Both Re(I) complexes were found to be weakly emitting with short excited state lifetimes. The electrochemistry of the complexes is defined by quasi-reversible Re oxidation and irreversible triazole-based ligand reduction processes.
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98
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Anderson CB, Elliott ABS, McAdam CJ, Gordon KC, Crowley JD. fac-Re(CO)3Cl Complexes of [2-(4-R-1H-1,2,3-Triazol-1-yl)methyl]pyridine Inverse “Click” Ligands: A Systematic Synthetic, Spectroscopic, and Computational Study. Organometallics 2013. [DOI: 10.1021/om300868k] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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99
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Cubanski JR, Cameron SA, Crowley JD, Blackman AG. Low symmetry pyrazole-based tripodal tetraamineligands: metal complexes and ligand decomposition reactions. Dalton Trans 2013. [DOI: 10.1039/c2dt32200e] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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100
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Lewis JEM, Crowley JD. Copper(II) Complexes of a Tripyridyl Ligand: Anion-Dependent Metallosupramolecular Structures. Aust J Chem 2013. [DOI: 10.1071/ch13379] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A series of copper(ii) complexes of the ligand 2,6-bis(pyridin-3-ylethynyl)pyridine have been synthesised and characterised by 1H and DOSY NMR, IR and UV-Vis spectroscopies, mass spectrometry, elemental analysis and single crystal X-ray diffraction. In solution these systems display almost identical spectroscopic properties, however the solid state structures are shown to vary widely, depending upon the choice of anion. The tetrafluoroborate salt was revealed to be a discrete Cu2L4 cage-like helicate. The tosylate salt, whilst of the same Cu2L4 stoichiometry, was shown to be a coordination polymer. Finally the nitrate salt structure was observed to be a discrete Cu2L2 metallocycle.
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