101
|
Lewis JEM, John McAdam C, Gardiner MG, Crowley JD. A facile “click” approach to functionalised metallosupramolecular architectures. Chem Commun (Camb) 2013; 49:3398-400. [DOI: 10.1039/c3cc41209a] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|
102
|
Brooker S, Gordon KC, Crowley JD, Lucas NT. Special issue dedicated to the seventh International Symposium of Macrocyclic and Supramolecular Chemistry (ISMSC-7). Supramol Chem 2012. [DOI: 10.1080/10610278.2012.686238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
103
|
Noor A, Lewis JE, Cameron SA, Moratti SC, Crowley JD. A multi-component CuAAC ‘click’ approach to an exo functionalised pyridyl-1,2,3-triazole macrocycle: synthesis, characterisation, Cu(I) and Ag(I) complexes. Supramol Chem 2012. [DOI: 10.1080/10610278.2012.688126] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
104
|
Wright JR, Shaffer KJ, McAdam CJ, Crowley JD. 3,5-Diferrocenylpyridine: Synthesis, characterisation, palladium(II) dichloride complex and electrochemistry. Polyhedron 2012. [DOI: 10.1016/j.poly.2012.01.028] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
|
105
|
Crowley JD, McMorran DA. “Click-Triazole” Coordination Chemistry: Exploiting 1,4-Disubstituted-1,2,3-Triazoles as Ligands. TOPICS IN HETEROCYCLIC CHEMISTRY 2012. [DOI: 10.1007/7081_2011_67] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
106
|
Lewis JEM, Gavey EL, Cameron SA, Crowley JD. Stimuli-responsive Pd2L4metallosupramolecular cages: towards targeted cisplatin drug delivery. Chem Sci 2012. [DOI: 10.1039/c2sc00899h] [Citation(s) in RCA: 323] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
|
107
|
Scott SØ, Gavey EL, Lind SJ, Gordon KC, Crowley JD. Self-assembled palladium(II) "click" cages: synthesis, structural modification and stability. Dalton Trans 2011; 40:12117-24. [PMID: 21792428 DOI: 10.1039/c1dt10551e] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Readily synthesised and functionalised di-1,2,3-triazole "click" ligands are shown to self-assemble into coordinatively saturated, quadruply stranded helical [Pd(2)L(4)](BF(4))(4) cages with Pd(II) ions. The cages have been fully characterised by elemental analysis, HR-ESMS, IR, (1)H, (13)C and DOSY NMR, DFT calculations, and in one case by X-ray crystallography. By exploiting the CuAAC "click" reaction we were able to rapidly generate a small family of di-1,2,3-triazole ligands with different core spacer units and peripheral substituents and examine how these structural modifications affected the formation of the [Pd(2)L(4)](BF(4))(4) cages. The use of both flexible (1,3-propyl) and rigid (1,3-phenyl) core spacer units led to the formation of discrete [Pd(2)L(4)](BF(4))(4) cage complexes. However, when the spacer unit of the di-1,2,3-triazole ligand was a 1,4-substituted-phenyl group steric interactions led to the formation of an oligomeric/polymeric species. By keeping the 1,3-phenyl core spacer constant the effect of altering the "click" ligands' peripheral substituents was also examined. It was shown that ligands with alkyl, phenyl, electron-rich and electron-poor benzyl substituents all quantitatively formed [Pd(2)L(4)](BF(4))(4) cage complexes. The results suggest that a wide range of functionalised palladium(II) "click" cages could be rapidly generated. These novel molecules may potentially find uses in catalysis, molecular recognition and drug delivery.
Collapse
|
108
|
Kilpin KJ, Gavey EL, McAdam CJ, Anderson CB, Lind SJ, Keep CC, Gordon KC, Crowley JD. Palladium(II) Complexes of Readily Functionalized Bidentate 2-Pyridyl-1,2,3-triazole “Click” Ligands: A Synthetic, Structural, Spectroscopic, and Computational Study. Inorg Chem 2011; 50:6334-46. [DOI: 10.1021/ic200789b] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
109
|
Kilpin KJ, Gower ML, Telfer SG, Jameson GB, Crowley JD. Toward the Self-Assembly of Metal−Organic Nanotubes Using Metal−Metal and π-Stacking Interactions: Bis(pyridylethynyl) Silver(I) Metallo-macrocycles and Coordination Polymers. Inorg Chem 2011; 50:1123-34. [DOI: 10.1021/ic1020059] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
|
110
|
Kilpin KJ, Paul USD, Lee AL, Crowley JD. Gold(i) “click” 1,2,3-triazolylidenes: synthesis, self-assembly and catalysis. Chem Commun (Camb) 2011; 47:328-30. [DOI: 10.1039/c0cc02185g] [Citation(s) in RCA: 164] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
|
111
|
Crowley JD, Lee AL, Kilpin KJ. 1,3,4-Trisubtituted-1,2,3-Triazol-5-ylidene 'Click' Carbene Ligands: Synthesis, Catalysis and Self-Assembly. Aust J Chem 2011. [DOI: 10.1071/ch11185] [Citation(s) in RCA: 144] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This review examines the use of the Cu(I)-catalyzed 1,3-cycloaddition of organic azides with terminal alkynes (the CuAAC ‘click’ reaction) for development of a novel family of abnormal/mesoionic N-heterocyclic carbenes and their corresponding metal complexes. These 1,3,4-trisubstituted-1,2,3-triazol-5-ylidenes have donor properties that are intermediate between the traditional Arduengo-type imidazol-2-ylidenes and more highly σ-donating abnormal carbenes, such as imidazol-4-ylidenes or pyrazolin-4-ylidenes. Metal complexes of the 1,3,4-trisubstituted-1,2,3-triazol-5-ylidenes have been used as catalysts for a variety of reactions including the CuAAC cycloaddition, Pd cross-couplings, and ring closing/ring opening metathesis. Additionally, ‘click’ carbene ligands have been used to generate self-assembled metallo-macrocycles and novel photosensitizers. The mild, modular CuAAC approach to these ligands should allow the rapid generation of libraries of 1,3,4-trisubstituted-1,2,3-triazol-5-ylidenes that can be further exploited to generate novel catalysts, metallo-pharmaceuticals and materials.
Collapse
|
112
|
Kilpin KJ, Horvath R, Jameson GB, Telfer SG, Gordon KC, Crowley JD. Pyridyl Gold(I) Alkynyls: A Synthetic, Structural, Spectroscopic, and Computational Study. Organometallics 2010. [DOI: 10.1021/om1003978] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
113
|
Kilpin KJ, Crowley JD. Palladium(II) and platinum(II) complexes of bidentate 2-pyridyl-1,2,3-triazole “click” ligands: Synthesis, properties and X-ray structures. Polyhedron 2010. [DOI: 10.1016/j.poly.2010.08.021] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
114
|
Crowley JD, Hänni KD, Leigh DA, Slawin AMZ. Diels-Alder active-template synthesis of rotaxanes and metal-ion-switchable molecular shuttles. J Am Chem Soc 2010; 132:5309-14. [PMID: 20334379 DOI: 10.1021/ja101029u] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A synthesis of [2]rotaxanes in which Zn(II) or Cu(II) Lewis acids catalyze a Diels-Alder cycloaddition to form the axle while simultaneously acting as the template for the assembly of the interlocked molecules is described. Coordination of the Lewis acid to a multidentate endotopic 2,6-di(methyleneoxymethyl)pyridyl- or bipyridine-containing macrocycle orients a chelated dienophile through the macrocycle cavity. Lewis acid activation of the double bond causes it to react with an incoming "stoppered" diene, affording the [2]rotaxane in up to 91% yield. Unusually for an active-template synthesis, the metal binding site "lives on" in these rotaxanes. This was exploited in the synthesis of a molecular shuttle containing two different ligating sites in which the position of the macrocycle could be switched by complexation with metal ions [Zn(II) and Pd(II)] with different preferred coordination geometries.
Collapse
|
115
|
Crowley JD, Goldup SM, Gowans ND, Leigh DA, Ronaldson VE, Slawin AMZ. An Unusual Nickel−Copper-Mediated Alkyne Homocoupling Reaction for the Active-Template Synthesis of [2]Rotaxanes. J Am Chem Soc 2010; 132:6243-8. [DOI: 10.1021/ja101121j] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
116
|
Gower ML, Crowley JD. Self-assembly of silver(i) metallomacrocycles using unsupported 1,4-substituted-1,2,3-triazole “click” ligands. Dalton Trans 2010; 39:2371-8. [DOI: 10.1039/b923211g] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
|
117
|
Crowley JD, Bandeen PH, Hanton LR. A one pot multi-component CuAAC “click” approach to bidentate and tridentate pyridyl-1,2,3-triazole ligands: Synthesis, X-ray structures and copper(II) and silver(I) complexes. Polyhedron 2010. [DOI: 10.1016/j.poly.2009.06.010] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
118
|
Crowley JD, Gavey EL. Use of di-1,4-substituted-1,2,3-triazole “click” ligands to self-assemble dipalladium(ii) coordinatively saturated, quadruply stranded helicate cages. Dalton Trans 2010; 39:4035-7. [DOI: 10.1039/c003683h] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
119
|
Crowley JD, Bandeen PH. A multicomponent CuAAC "click" approach to a library of hybrid polydentate 2-pyridyl-1,2,3-triazole ligands: new building blocks for the generation of metallosupramolecular architectures. Dalton Trans 2009:612-23. [PMID: 20024000 DOI: 10.1039/b911276f] [Citation(s) in RCA: 159] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A one pot, multicomponent CuAAC reaction has been exploited for the safe generation of alkyl, benzyl or aryl linked polydentate pyridyl-1,2,3-triazole ligands from their corresponding halides, sodium azide and alkynes in excellent yields. The ligands have been fully characterised by elemental analysis, HR-ESMS, IR, (1)H and (13)C NMR and in two cases the structures were confirmed by X-ray crystallography. Additionally, we have examined the Ag(I) coordination chemistry of these ligands and found, using HR-ESMS, (1)H NMR, and X-ray crystallography, that both discrete and polymeric metallosupramolecular architectures can be formed.
Collapse
|
120
|
Crowley JD, Goldup SM, Lee AL, Leigh DA, McBurney RT. Active metal template synthesis of rotaxanes, catenanes and molecular shuttles. Chem Soc Rev 2009; 38:1530-41. [PMID: 19587949 DOI: 10.1039/b804243h] [Citation(s) in RCA: 519] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Active metal template synthesis is a powerful new strategy for the construction of rotaxanes, catenanes and other mechanically interlocked molecular structures. The key feature is that the metal plays a dual role during the assembly of the interlocked architecture, acting as both a template for entwining or threading the components and as a catalyst for capturing the interlocked final product by covalent bond formation. Unlike traditional "passive" metal template methods to rotaxanes and catenanes, permanent recognition motifs are not required on each of the components to be interlocked (i.e., the assembly can be traceless) and the template can often be used in sub-stoichiometric quantities. Since its inception in 2006, a rapidly growing number of different metal-catalysed reactions have proven suitable for the active metal template synthesis of both rotaxanes and catenanes, including the copper(i)-catalysed terminal alkyne-azide cycloaddition (the CuAAC "click" reaction), palladium- and copper-catalysed alkyne homocouplings and heterocouplings, and palladium-catalysed oxidative Heck couplings and Michael additions. In addition to simple rotaxanes and catenanes, the synthetic strategy has been used to construct switchable molecular shuttles with weak intercomponent interactions (a requirement for fast shuttling) and to provide insight into the mechanisms of transition metal-catalysed reactions. In this tutorial review we highlight the utility and potential of the early examples of the active metal template strategy in mechanically interlocked molecule synthesis.
Collapse
|
121
|
Crowley JD, Bandeen PH, Hanton LR. 1-(3-Bromo-prop-yl)-4-(2-pyrid-yl)-1H-1,2,3-triazole. Acta Crystallogr Sect E Struct Rep Online 2009; 65:o999-o1000. [PMID: 21584033 PMCID: PMC2977690 DOI: 10.1107/s1600536809012148] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2009] [Accepted: 04/01/2009] [Indexed: 11/11/2022]
Abstract
In the structure of the title compound, C(10)H(11)BrN(4), the plane of the substituted 1,2,3-triazole ring is tilted by 14.84 (10)° with respect to the mean plane of the pyridine ring. The pyridine and closest triazole N atoms adopt an anti arrangement which removes any lone pair-lone pair repulsions between the N atoms. This conformation is further stabilized by weak intermolecular C-H⋯N inter-actions. There are two mol-ecules in the unit cell, which form a centrosymmetric head-to-tail dimer. The dimers are stabilized through π-π inter-actions [centroid-centroid distance = 3.733 (4) Å and mean inter-planar distance = 3.806 (12) Å] between the substituted 1,2,3-triazole ring and the pyridine rings in adjacent mol-ecules. Each dimer inter-acts with two neighbouring dimers above and below, forming a slipped stack of dimers through the crystal. The 3-bromo-propyl chain sits over the pyridine ring of a neighbouring mol-ecule and the triazole rings of nearby mol-ecules are adjacent.
Collapse
|
122
|
Crowley JD, Leigh DA, Lusby PJ, McBurney RT, Perret-Aebi LE, Petzold C, Slawin AMZ, Symes MD. A Switchable Palladium-Complexed Molecular Shuttle and Its Metastable Positional Isomers. J Am Chem Soc 2007; 129:15085-90. [DOI: 10.1021/ja076570h] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
123
|
Crowley JD, Hänni KD, Lee AL, Leigh DA. [2]Rotaxanes through Palladium Active-Template Oxidative Heck Cross-Couplings. J Am Chem Soc 2007; 129:12092-3. [PMID: 17877356 DOI: 10.1021/ja075219t] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
124
|
Aucagne V, Berna J, Crowley JD, Goldup SM, Hänni KD, Leigh DA, Lusby PJ, Ronaldson VE, Slawin AMZ, Viterisi A, Walker DB. Catalytic "active-metal" template synthesis of [2]rotaxanes, [3]rotaxanes, and molecular shuttles, and some observations on the mechanism of the cu(i)-catalyzed azide-alkyne 1,3-cycloaddition. J Am Chem Soc 2007; 129:11950-63. [PMID: 17845039 DOI: 10.1021/ja073513f] [Citation(s) in RCA: 224] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A synthetic approach to rotaxane architectures is described in which metal atoms catalyze covalent bond formation while simultaneously acting as the template for the assembly of the mechanically interlocked structure. This "active-metal" template strategy is exemplified using the Huisgen-Meldal-Fokin Cu(I)-catalyzed 1,3-cycloaddition of azides with terminal alkynes (the CuAAC "click" reaction). Coordination of Cu(I) to an endotopic pyridine-containing macrocycle allows the alkyne and azide to bind to metal atoms in such a way that the metal-mediated bond-forming reaction takes place through the cavity of the macrocycle--or macrocycles--forming a rotaxane. A variety of mono- and bidentate macrocyclic ligands are demonstrated to form [2]rotaxanes in this way, and by adding pyridine, the metal can turn over during the reaction, giving a catalytic active-metal template assembly process. Both the stoichiometric and catalytic versions of the reaction were also used to synthesize more complex two-station molecular shuttles. The dynamics of the translocation of the macrocycle by ligand exchange in these two-station shuttles could be controlled by coordination to different metal ions (rapid shuttling is observed with Cu(I), slow shuttling with Pd(II)). Under active-metal template reaction conditions that feature a high macrocycle:copper ratio, [3]rotaxanes (two macrocycles on a thread containing a single triazole ring) are also produced during the reaction. The latter observation shows that under these conditions the mechanism of the Cu(I)-catalyzed terminal alkyne-azide cycloaddition involves a reactive intermediate that features at least two metal ions.
Collapse
|
125
|
Berná J, Crowley JD, Goldup SM, Hänni KD, Lee AL, Leigh DA. A Catalytic Palladium Active-Metal Template Pathway to [2]Rotaxanes. Angew Chem Int Ed Engl 2007; 46:5709-13. [PMID: 17594702 DOI: 10.1002/anie.200701678] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
126
|
Crowley JD, Steele IM, Bosnich B. Protonmotive force: development of electrostatic drivers for synthetic molecular motors. Chemistry 2007; 12:8935-51. [PMID: 16823783 DOI: 10.1002/chem.200500519] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Ferrocene has been investigated as a platform for developing protonmotive electrostatic drivers for molecular motors. When two 3-pyridine groups are substituted to the (rapidly rotating) cyclopentadienyl (Cp) rings of ferrocene, one on each Cp, it is shown that the (Cp) eclipsed, pi-stacked rotameric conformation is preferred both in solution and in the solid state. Upon quaternization of both of the pyridines substituents, either by protonation or by alkylation, it is shown that the preferred rotameric conformation is one where the pyridinium groups are rotated away from the fully pi-stacked conformation. Electrostatic calculations indicate that the rotation is caused by the electrostatic repulsion between the charges. Consistently, when the pi-stacking energy is increased pi-stacked population increases, and conversely when the electrostatic repulsion is increased pi-stacked population is decreased. This work serves to provide an approximate estimate of the amount of torque that the electrostatically driven ferrocene platform can generate when incorporated into a molecular motor. The overall conclusion is that the electrostatic interaction energy between dicationic ferrocene dipyridyl systems is similar to the pi-stacking interaction energy and, consequently, at least tricationic systems are required to fully uncouple the pi-stacked pyridine substituents.
Collapse
|
127
|
Crowley JD, Steele IM, Bosnich B. Molecular Recognition - Allosterism Generated by Weak Host-Guest Interactions in Molecular Rectangles. Eur J Inorg Chem 2005. [DOI: 10.1002/ejic.200500393] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
128
|
Crowley JD, Bosnich B. Molecular Recognition: Use of Metal‐Containing Molecular Clefts for Supramolecular Self‐Assembly and Host–Guest Formation. Eur J Inorg Chem 2005. [DOI: 10.1002/ejic.200500091] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
129
|
Crowley JD, Steele IM, Bosnich B. Supramolecular Recognition Forces: An Examination of Weak Metal−Metal Interactions in Host−Guest Formation. Inorg Chem 2005; 44:2989-91. [PMID: 15847397 DOI: 10.1021/ic0481531] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Molecular receptors consisting of two parallel-disposed terpy-M-Cl units (M = Pd2+, Pt2+) are used to form host-guest adducts with aromatic molecules and with neutral square-planar Pt2+ complexes. Host-guest formation is controlled by several factors including pi-pi interactions and, in some cases, weak Pt-Pt interactions between the host and the guest. This latter interaction was examined by comparing the host-guest stability of adducts formed by isoelectronic Pt2+ and Au3+ complexes with the Pt2+ receptor. Consistently, the former is more stable.
Collapse
|
130
|
Crowley JD, Goshe AJ, Steele IM, Bosnich B. Supramolecular Recognition: Protonmotive-Driven Switches or Motors? Chemistry 2004; 10:1944-55. [PMID: 15079834 DOI: 10.1002/chem.200305620] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A dicationic molecular receptor bearing two cofacially disposed terpyridyl-Pd-Cl units forms stable 1:1 host-guest complexes with planar, neutral platinum(II) complexes. When the guest is modified to incorporate a pyridine group, the now basic guest is protonated by trifluoroacetic acid in acetonitrile solutions. The basic yellow guest forms a stable, deep red 1:1 host-guest complex with the yellow palladium receptor. Addition of trifluoroacetic acid to this host-guest complex leads to the displacement of the guest from the receptor. It is proposed that the dissociation of the guest is caused by electrostatic repulsion between the dicationic receptor and the positively charged protonated guest. Addition of base restores the host-guest complex. This protonmotive translocation of the guest from the host to the solution is discussed in terms of the mechanisms that drive molecular motors, the power stroke and the Brownian ratchet. It is concluded that the system is best described as a molecular switch that operates by the same mechanism as one stroke of a molecular motor
Collapse
|
131
|
Crowley JD, Goshe AJ, Bosnich B. Molecular recognition. Electrostatic effects in supramolecular self-assembly. Chem Commun (Camb) 2003:392-3. [PMID: 12613628 DOI: 10.1039/b210957c] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A di-positively charged metal-based receptor is shown to form 1:1 or 2:1 association complexes with rigid, linear two-site guests depending on the site separation, suggesting that electrostatic repulsion controls the association nuclearity.
Collapse
|
132
|
Crowley JD, Goshe AJ, Bosnich B. Molecular recognition. Self-assembly of molecular trigonal prisms and their host–guest adducts. Chem Commun (Camb) 2003:2824-5. [PMID: 14651123 DOI: 10.1039/b307385h] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two supramolecular trigonal prisms, each bearing three molecular clefts are shown to form 1:6 and 1:7 host-guest complexes with 9-methylanthracene and one of the prisms forms a 1:2 host-guest complex with a tritopic tri-anthracene guest that registers with the recognition sites of the host.
Collapse
|
133
|
Crowley JD, Shelton J, Iverson AJ, Burton MP, Dalrymple NC, Bishoff JT. Laparoscopic and computed tomography-guided percutaneous radiofrequency ablation of renal tissue: acute and chronic effects in an animal model. Urology 2001; 57:976-80. [PMID: 11337311 DOI: 10.1016/s0090-4295(00)01129-8] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES To evaluate the laparoscopic and percutaneous delivery of impedance-based radiofrequency ablation (RFA) of the kidney by studying the acute and chronic clinical, radiographic, and histopathologic effects in the porcine model. METHODS Eight kidneys from 4 pigs underwent laparoscopic RFA. Six kidneys from 3 additional pigs received computed tomography (CT)-guided, percutaneous RFA. CT scans were performed immediately after RFA and before harvest at 2 hours, 24 hours, 3 weeks, and 13 weeks. The gross, radiographic, and histopathologic changes were recorded for each period. RESULTS Grossly, the RFA lesions were sharply demarcated, measuring 3 to 5 cm. Two major complications (14%) occurred (one urinoma, one psoas muscle injury) in 14 ablations. No deaths or significant blood loss occurred as a result of RFA. Radiographically, the immediate CT scanning demonstrated small perinephric hematomas and wedge-shaped defects. Delayed CT showed nonenhancing defects up to 5 cm. Color-flow and power Doppler were unable to distinguish significant tissue changes during RFA. The histopathologic evaluation revealed marked inflammation surrounding the necrotic regions in the early lesions; chronic lesions were characterized by dense fibrosis. The tissue temperatures ranged from 62 degrees to 118 degrees C in the area of ablation. CONCLUSIONS RFA is readily delivered laparoscopically or percutaneously with minimal morbidity. Impedance-based application of radiofrequency energy allows monitoring and control of ablation. Using a multi-antenna probe, areas of tissue up to 5 cm can be completely destroyed. The RFA lesion can be monitored as a nonenhancing cortical defect on CT.
Collapse
|
134
|
Crowley JD, Traynor DA, Weatherburn DC. Enzymes and proteins containing manganese: an overview. METAL IONS IN BIOLOGICAL SYSTEMS 2000; 37:209-78. [PMID: 10693136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
|
135
|
Crowley JD. Syntometrine and immediate delivery of the placenta. THE NEW ZEALAND MEDICAL JOURNAL 1965; 64:499-502. [PMID: 5214186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|