51
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Cyclic tetranuclear half-sandwich ruthenium(II) complexes with 4,7-phenanthroline and hydroxo bridges: Crystal structure, solution behaviour and binding to nucleosides. J Inorg Biochem 2008; 102:1025-32. [DOI: 10.1016/j.jinorgbio.2007.11.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2007] [Revised: 11/05/2007] [Accepted: 11/21/2007] [Indexed: 11/17/2022]
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52
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Skarżyńska A, Siczek M. Reactivity of oxo-rhenium precursor trans-ReOCl3(OPPh3)(SMe2) with diaza heterocyclic congeners: Synthesis and spectroscopic characterization of mono and dinuclear compounds. Polyhedron 2008. [DOI: 10.1016/j.poly.2008.02.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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53
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Donghi D, D’Alfonso G, Mauro M, Panigati M, Mercandelli P, Sironi A, Mussini P, D’Alfonso L. A New Class of Luminescent Tricarbonyl Rhenium(I) Complexes Containing Bridging 1,2-Diazine Ligands: Electrochemical, Photophysical, and Computational Characterization. Inorg Chem 2008; 47:4243-55. [DOI: 10.1021/ic7023692] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Daniela Donghi
- Dipartimento di Chimica Inorganica, Metallorganica e Analitica (DCIMA), Università di Milano, via Venezian 21, I-20133 Milano, Italy, Dipartimento di Chimica Strutturale e Stereochimica Inorganica (DCSSI), Università di Milano, via Venezian 21, I-20133 Milano, Italy, Dipartimento di Chimica Fisica ed Elettrochimica (DCFE), Università di Milano, via Golgi 19, I-20133 Milano, Italy, Dipartimento di Fisica, Università di Milano-Bicocca, piazza della Scienza 6, I-20126 Milano, Italy, Centro di Eccellenza
| | - Giuseppe D’Alfonso
- Dipartimento di Chimica Inorganica, Metallorganica e Analitica (DCIMA), Università di Milano, via Venezian 21, I-20133 Milano, Italy, Dipartimento di Chimica Strutturale e Stereochimica Inorganica (DCSSI), Università di Milano, via Venezian 21, I-20133 Milano, Italy, Dipartimento di Chimica Fisica ed Elettrochimica (DCFE), Università di Milano, via Golgi 19, I-20133 Milano, Italy, Dipartimento di Fisica, Università di Milano-Bicocca, piazza della Scienza 6, I-20126 Milano, Italy, Centro di Eccellenza
| | - Matteo Mauro
- Dipartimento di Chimica Inorganica, Metallorganica e Analitica (DCIMA), Università di Milano, via Venezian 21, I-20133 Milano, Italy, Dipartimento di Chimica Strutturale e Stereochimica Inorganica (DCSSI), Università di Milano, via Venezian 21, I-20133 Milano, Italy, Dipartimento di Chimica Fisica ed Elettrochimica (DCFE), Università di Milano, via Golgi 19, I-20133 Milano, Italy, Dipartimento di Fisica, Università di Milano-Bicocca, piazza della Scienza 6, I-20126 Milano, Italy, Centro di Eccellenza
| | - Monica Panigati
- Dipartimento di Chimica Inorganica, Metallorganica e Analitica (DCIMA), Università di Milano, via Venezian 21, I-20133 Milano, Italy, Dipartimento di Chimica Strutturale e Stereochimica Inorganica (DCSSI), Università di Milano, via Venezian 21, I-20133 Milano, Italy, Dipartimento di Chimica Fisica ed Elettrochimica (DCFE), Università di Milano, via Golgi 19, I-20133 Milano, Italy, Dipartimento di Fisica, Università di Milano-Bicocca, piazza della Scienza 6, I-20126 Milano, Italy, Centro di Eccellenza
| | - Pierluigi Mercandelli
- Dipartimento di Chimica Inorganica, Metallorganica e Analitica (DCIMA), Università di Milano, via Venezian 21, I-20133 Milano, Italy, Dipartimento di Chimica Strutturale e Stereochimica Inorganica (DCSSI), Università di Milano, via Venezian 21, I-20133 Milano, Italy, Dipartimento di Chimica Fisica ed Elettrochimica (DCFE), Università di Milano, via Golgi 19, I-20133 Milano, Italy, Dipartimento di Fisica, Università di Milano-Bicocca, piazza della Scienza 6, I-20126 Milano, Italy, Centro di Eccellenza
| | - Angelo Sironi
- Dipartimento di Chimica Inorganica, Metallorganica e Analitica (DCIMA), Università di Milano, via Venezian 21, I-20133 Milano, Italy, Dipartimento di Chimica Strutturale e Stereochimica Inorganica (DCSSI), Università di Milano, via Venezian 21, I-20133 Milano, Italy, Dipartimento di Chimica Fisica ed Elettrochimica (DCFE), Università di Milano, via Golgi 19, I-20133 Milano, Italy, Dipartimento di Fisica, Università di Milano-Bicocca, piazza della Scienza 6, I-20126 Milano, Italy, Centro di Eccellenza
| | - Patrizia Mussini
- Dipartimento di Chimica Inorganica, Metallorganica e Analitica (DCIMA), Università di Milano, via Venezian 21, I-20133 Milano, Italy, Dipartimento di Chimica Strutturale e Stereochimica Inorganica (DCSSI), Università di Milano, via Venezian 21, I-20133 Milano, Italy, Dipartimento di Chimica Fisica ed Elettrochimica (DCFE), Università di Milano, via Golgi 19, I-20133 Milano, Italy, Dipartimento di Fisica, Università di Milano-Bicocca, piazza della Scienza 6, I-20126 Milano, Italy, Centro di Eccellenza
| | - Laura D’Alfonso
- Dipartimento di Chimica Inorganica, Metallorganica e Analitica (DCIMA), Università di Milano, via Venezian 21, I-20133 Milano, Italy, Dipartimento di Chimica Strutturale e Stereochimica Inorganica (DCSSI), Università di Milano, via Venezian 21, I-20133 Milano, Italy, Dipartimento di Chimica Fisica ed Elettrochimica (DCFE), Università di Milano, via Golgi 19, I-20133 Milano, Italy, Dipartimento di Fisica, Università di Milano-Bicocca, piazza della Scienza 6, I-20126 Milano, Italy, Centro di Eccellenza
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Jiang H, Ma JF, Zhang WL, Liu YY, Yang J, Ping GJ, Su ZM. Metal–Organic Frameworks Containing Flexible Bis(benzimidazole) Ligands. Eur J Inorg Chem 2008. [DOI: 10.1002/ejic.200700833] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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56
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Thanasekaran P, Wu JY, Manimaran B, Rajendran T, Chang IJ, Rajagopal S, Lee GH, Peng SM, Lu KL. Aggregate of Alkoxy-Bridged Re(I)-Rectangles as a Probe for Photoluminescence Quenching. J Phys Chem A 2007; 111:10953-60. [DOI: 10.1021/jp0742315] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- P. Thanasekaran
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan, Department of Chemistry, National Taiwan Normal University, Taipei 117, Taiwan, Department of Chemistry, National Taiwan University, Taipei 107, Taiwan, and School of Chemistry, Madurai Kamaraj University, Madurai, 625 021, India
| | - Jing-Yun Wu
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan, Department of Chemistry, National Taiwan Normal University, Taipei 117, Taiwan, Department of Chemistry, National Taiwan University, Taipei 107, Taiwan, and School of Chemistry, Madurai Kamaraj University, Madurai, 625 021, India
| | - Bala. Manimaran
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan, Department of Chemistry, National Taiwan Normal University, Taipei 117, Taiwan, Department of Chemistry, National Taiwan University, Taipei 107, Taiwan, and School of Chemistry, Madurai Kamaraj University, Madurai, 625 021, India
| | - T. Rajendran
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan, Department of Chemistry, National Taiwan Normal University, Taipei 117, Taiwan, Department of Chemistry, National Taiwan University, Taipei 107, Taiwan, and School of Chemistry, Madurai Kamaraj University, Madurai, 625 021, India
| | - I-Jy Chang
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan, Department of Chemistry, National Taiwan Normal University, Taipei 117, Taiwan, Department of Chemistry, National Taiwan University, Taipei 107, Taiwan, and School of Chemistry, Madurai Kamaraj University, Madurai, 625 021, India
| | - S. Rajagopal
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan, Department of Chemistry, National Taiwan Normal University, Taipei 117, Taiwan, Department of Chemistry, National Taiwan University, Taipei 107, Taiwan, and School of Chemistry, Madurai Kamaraj University, Madurai, 625 021, India
| | - Gene-Hsiang Lee
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan, Department of Chemistry, National Taiwan Normal University, Taipei 117, Taiwan, Department of Chemistry, National Taiwan University, Taipei 107, Taiwan, and School of Chemistry, Madurai Kamaraj University, Madurai, 625 021, India
| | - Shie-Ming Peng
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan, Department of Chemistry, National Taiwan Normal University, Taipei 117, Taiwan, Department of Chemistry, National Taiwan University, Taipei 107, Taiwan, and School of Chemistry, Madurai Kamaraj University, Madurai, 625 021, India
| | - Kuang-Lieh Lu
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan, Department of Chemistry, National Taiwan Normal University, Taipei 117, Taiwan, Department of Chemistry, National Taiwan University, Taipei 107, Taiwan, and School of Chemistry, Madurai Kamaraj University, Madurai, 625 021, India
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57
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Panigati M, Donghi D, D'Alfonso G, Mercandelli P, Sironi A, D'Alfonso L. Luminescent Hydrido-Carbonyl Clusters of Rhenium Containing Bridging 1,2-Diazine Ligands. Inorg Chem 2006; 45:10909-21. [PMID: 17173450 DOI: 10.1021/ic061467z] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The reaction of the electronically unsaturated (56 valence electrons, ve) tetrahedral cluster [Re4(mu3-H)4(CO)12] (1) with pyridazine (pydz) gives as the main initial product the tetranuclear cluster [Re4(mu-H)4(mu-pydz)(pydz)2(CO)12] (2a), with 64 ve and four hydrogen-bridged metal-metal interactions, with a spiked-triangle geometry. One of the three pydz ligands bridges, in a cis configuration, the cluster edge opposite to the vertex bearing the spike, as indicated by the X-ray single-crystal analysis. This species slowly decomposes, affording the dinuclear unsaturated (32 ve) complex [Re2(mu-H)2(mu-pydz)(CO)6] (3a) and two isomers of the tetranuclear cluster [Re4(mu-H)4(mu-pydz)2(CO)12] (64 ve), sharing an unusual square cluster geometry and differing in the trans (major, 85%, 4a) or cis (4a') configuration of the bridging pydz ligands. The structures of 3a and 4a have been ascertained by X-ray analysis, while the characterization of 4a' was hampered by its instability (slowly transforming into 3a in THF solution). Both the dimer and the square cluster 4a are also formed directly (and quickly) from 1, being present in solution since the beginning of the reaction. Cluster 4a is the main final reaction product. The reaction with phthalazine follows a similar course, with some differences in the relative amount of the final products 3b and 4b. Most of the novel complexes are able to emit light in solution at room temperature, and photophysical measurements were performed in CH2Cl2 solution on the main stable reaction products (i.e., the dinuclear species 3a and 3b and the trans square clusters 4a and 4b). The emission was in the range of 580-645 nm, from MLCT excited states, with lifetimes on the order of a hundred nanoseconds (50-473 ns). The quantum yields were 1 order of magnitude higher for the squares (1.7 and 1.3% for 4a and 4b, respectively, in CH2Cl2) than for the dinuclear complexes ( approximately 0.1%). In the case of 4a, a blue shift and an increase of the emission intensity were observed upon decreasing the solvent polarity.
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Affiliation(s)
- Monica Panigati
- Dipartimento di Chimica Inorganica, Metallorganica e Analitica, Università di Milano and INSTM UdR di Milano, Via Venezian 21, 20133 Milan, Italy
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58
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Sathiyendiran M, Liao RT, Thanasekaran P, Luo TT, Venkataramanan NS, Lee GH, Peng SM, Lu KL. Gondola-Shaped Luminescent Tetrarhenium Metallacycles with Crown-Ether-like Multiple Recognition Sites. Inorg Chem 2006; 45:10052-4. [PMID: 17140209 DOI: 10.1021/ic061886w] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The self-assembly of gondola-shaped tetrarhenium metallacyclophanes was achieved in near quantitative yield from Re(CO)3 corners, a ditopic heterocyclic clip, and a bischelating-bridging unit using an orthogonal-bonding approach. The highly luminescent metallacycles contain crown-ether-like recognition sites, which are capable of selectively recognizing metal ions and planar aromatic molecules.
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59
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Thanasekaran P, Liao RT, Manimaran B, Liu YH, Chou PT, Rajagopal S, Lu KL. Photoluminescence Electron-Transfer Quenching of Rhenium(I) Rectangles with Amines. J Phys Chem A 2006; 110:10683-9. [PMID: 16970357 DOI: 10.1021/jp060391p] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Electron-transfer (ET) reactions from aromatic amines to excited states of rhenium(I)-based molecular rectangles [{Re(CO)3(mu-bpy)Br}{Re(CO)3(mu-L)Br}]2 (bpy = 4,4'-bipyridine, L = 4,4'-dipyridylacetylene (dpa), I; L = 4,4'-dipyridylbutadiyne (dpb), II; and L = 1,4-bis(4'-pyridylethynyl)benzene (bpeb), III) were investigated in a dichloromethane solution using luminescence quenching techniques. Direct evidence for the ET reaction was obtained from the detection of the amine cation radical in this system using time-resolved transient absorption spectroscopy. The values of the luminescence quenching rate constants, kq, of the 3MLCT excited state of Re(I) rectangles with amines were found to be higher than those for the monomeric Re(I) complexes and other Re(I)-based metallacyclophanes. The observed kq values were correlated well with the driving force (Delta G degrees) for the ET reactions. In addition, a semiclassical theory of ET was successfully applied to the photoluminescence quenching of Re(I) rectangles with amines.
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Affiliation(s)
- P Thanasekaran
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan
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60
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Casanova M, Zangrando E, Munini F, Iengo E, Alessio E. fac-[Re(CO)3(dmso-O)3](CF3SO3): a new versatile and efficient Re(i) precursor for the preparation of mono and polynuclear compounds containing fac-[Re(CO)3]+ fragments. Dalton Trans 2006:5033-45. [PMID: 17060989 DOI: 10.1039/b609853c] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We show here that the new complex fac-[Re(CO)3(dmso-O)3](CF3SO3) (1), efficiently prepared in one step from [ReBr(CO)5] and featuring a broad range of solubility, is, in general, a better precursor for the one-step synthesis of mono- and polynuclear inorganic compounds containing fac-[Re(CO)3]+ fragments compared to the commonly used (NEt4)2fac-[ReBr3(CO)3] and fac-[Re(CO)3(CH3CN)3](Y) (Y = PF6, BF4, ClO4) species. Compound 1 is the first example of a Re(I)-dmso complex structurally characterized and confirms the rule that dmso is always O-bonded when trans to CO. The reactivity of 1 was tested in the one-step preparation of several new and known complexes. The O-bonded sulfoxides of 1 are replaced under mild conditions by tri- (L3) and bidentate ligands (L2) to produce fac-[Re(CO)3(L3)]+ and fac-[Re(CO)3(L2)(dmso-O)]+ compounds, respectively. An excess of monodentate ligands (L) and more forcing conditions are needed to prepare fac-[Re(CO)3(L)3]+ compounds. The new compounds include fac-[Re(CO)3(bipy)(dmso-O)](CF3SO3) (4), that turned out to be an excellent precursor for binding the luminescent fac-[Re(CO)3(bipy)]+ fragment to polytopic ligands for the construction of more elaborate assemblies. One example reported here is the two-step preparation of fac-[{Re(CO)3(bipy)}(mu-4,4'-bipy){Ru(TPP)(CO)}](CF3SO3) (8) (TPP = tetraphenylporphyrin). The X-ray structures of the new compounds 1, 4, of the bis-porphyrin complex fac-[Re(CO)3Cl(4'MPyP)2] (13) (4'MPyP = 5-(4'pyridyl)-10,15,20-triphenylporphyrin), and of the rhenium-cyclophane [{(CO)3Re(mu-OH)2Re(CO)3}2(micro-4,4'-bipy)2] (15), among others, are described. Compound 1 might find useful applications in supramolecular chemistry (metal-mediated assembly of large architectures), in the in situ preparation of stable Re compounds to be used in nuclear medicine, and for the labeling of biomolecules.
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Affiliation(s)
- Massimo Casanova
- Dipartimento di Scienze Chimiche, Università di Trieste, Via L. Giorgieri 1, 34127 Trieste, Italy
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Tzeng BC, Yeh HT, Wu YL, Kuo JH, Lee GH, Peng SM. Supramolecular Assembly of Gold(I) Complexes of Diphosphines and N,N‘-Bis-4-methylpyridyl Oxalamide. Inorg Chem 2005; 45:591-8. [PMID: 16411694 DOI: 10.1021/ic051297a] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report herein the supramolecular assembly and spectroscopic and luminescent properties of gold(I) complexes of diphosphines (dppm [bis(diphenylphosphino)methane], dppp [1,3-bis(diphenylphosphino)propane], and dpppn [1,5-bis(diphenylphosphino)pentane]) and N,N'-bis-4-methylpyridyl oxalamide (L). The dppm and dppp cases form the rectangular structures, [dppm(Au(2))L](2)(ClO(4))(4) and [dppp(Au(2))L](2)(ClO(4))(4), with four gold(I) ions at the corners, as well as two L and two dppm or dppp ligands as edges, featuring 38- and 42-membered rings for the former and the latter, respectively. Remarkably, the packing of the dppp complexes shows interesting one-dimensional rectangular channels in the solid state, most likely due to intermolecular pi...pi interactions. The dpppn complex has been structurally characterized as a one-dimensional coordination polymer, {[(dpppn)(3.5)(Au(7))L(3.5)](PF(6))(7)}. The absorptions and emissions of the compounds are in general due to intraligand transitions, but aurophilic or pi...pi interactions could also make partial contributions. The dipyridyl amide system with the amides incorporated into the bridging ligands as well as the one-dimensional rectangular channels in the solid state for the dppp-based rectangle make this a promising family of metal-containing cyclic peptides in crystal engineering and molecular-recognition studies.
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Affiliation(s)
- Biing-Chiau Tzeng
- Department of Chemistry and Biochemistry, National Chung Cheng University, 168, University Road, Min-Hsiung, Chia-Yi, Taiwan 621.
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Pothiraja R, Sathiyendiran M, Butcher RJ, Murugavel R. Non-Interpenetrating Transition Metal Diorganophosphate 2-Dimensional Rectangular Grids from Their 1-Dimensional Wires: Structural Transformations under Mild Conditions. Inorg Chem 2005; 44:6314-23. [PMID: 16124811 DOI: 10.1021/ic050742z] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The manganese, cobalt, and cadmium complexes [M(dtbp)2]n (M = Mn (1) and Co 2) and [Cd(dtbp)2(H2O)]n (3) (dtbp = di-tert-butyl phosphate), which exist as one-dimensional molecular wires, transform to non-interpenetrating rectangular grids [M(dtbp)2(bpy)2.2H2O]n (M = Mn (4), Co (5), and Cd (6)) by the addition of 4,4-bipyridine (bpy) at room temperature. Products 4-6 have also been prepared by a room-temperature reaction or by solvothermal synthesis in methanol through a direct reaction between the metal acetate, di-tert-butyl phosphate, and 4,4'-bipyridine (bpy) in a 1:2:2 molar ratio. Single-crystal X-ray structure determination of 4-6 shows that these compounds are composed of octahedral transition metal ions woven into a two-dimensional grid structure with the help of bpy spacer ligands. The axial coordination sites at the metal are occupied by bulky unidentate dtbp ligands, which prevent any interpenetration of the individual grids. The change of reaction conditions from solvothermal to hydrothermal, for the attempted synthesis of a magnesium grid structure, however leads to the isolation of an organic phosphate [(H2bpy)(H2PO4)2] (7) and an inorganic phosphate [Mg(HPO4)(OH2)3] (8). Compound 7 can also be prepared quantitatively from a direct reaction between bpy and H3PO4. The new organic phosphate 7 is a unique example of a phosphate material with alternating layers of [H2bpy]2+ cations and [H2PO4]- anions that are held together by hydrogen bonds. Solid-state thermal decomposition of 4-6 produced the respective metaphosphate materials [M(PO3)2] (M = Mn (9), Co (10), and Cd (11)). All new metal-organic phosphates have been characterized by elemental analysis, thermal analysis (TGA, DTA, DSC), and IR and NMR spectroscopy. The metaphosphate ceramic materials were characterized by IR spectral and powder X-ray diffraction studies.
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Yutaka T, Obara S, Ogawa S, Nozaki K, Ikeda N, Ohno T, Ishii Y, Sakai K, Haga MA. Syntheses and Properties of Emissive Iridium(III) Complexes with Tridentate Benzimidazole Derivatives. Inorg Chem 2005; 44:4737-46. [PMID: 15962982 DOI: 10.1021/ic048622z] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of novel emissive Ir(III) complexes having the coordination environments of [Ir(N--N--N)2]3+, [Ir(N--N--N)(N--N)Cl]2+, and [Ir(N--N--N)(N--C--N)]2+ with 2,6-bis(1-methyl-benzimidazol-2-yl)pyridine (L1, N--N--N), 1,3-bis(1-methyl-benzimidazol-2-yl)benzene (L2H, N--C--N), 4'-(4-methylphenyl)-2,2':6',2' '-terpyridine (ttpy, N--N--N), and 2,2'-bipyridine (bpy, N--N) have been synthesized and their photophysical and electrochemical properties studied. The Ir(III) complexes exhibited phosphorescent emissions in the 500-600 nm region, with lifetimes ranging from approximately 1-10 micros at 295 K. Analysis of the 0-0 energies and the redox potentials indicated that the lowest excited state of [Ir(L1)(L2)]2+ possessed the highest contribution of 3MLCT (MLCT = metal-to-ligand charge transfer) among the Ir(III) complexes, reflecting the sigma-donating ability of the tridentate ligand, ttpy < L1 < L2. The emission quantum yields (phi) of the Ir(III) complexes ranged from 0.037 to 0.19, and the highest phi value (0.19) was obtained for [Ir(L1)(bpy)Cl]2+. Radiative rate constants (k(r)) were 1.2 x 10(4) s(-1) for [Ir(ttpy)2]3+, 3.7 x 10(4) s(-1) for [Ir(L1)(bpy)Cl]2+, 3.8 x 10(4) s(-1) for [Ir(ttpy)(bpy)Cl]2+, 3.9 x 10(4) s(-1) for [Ir(L1)2]3+, and 6.6 x 10(4) s(-1) for [Ir(L1)(L2)]2+. The highest radiative rate for [Ir(L1)(L2)]2+ with the highest contribution of 3MLCT could be explained in terms of the singlet-triplet mixing induced by spin-orbit coupling of 5d electrons in the MLCT electronic configurations.
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Affiliation(s)
- Tomona Yutaka
- Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
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Thanasekaran P, Liao RT, Liu YH, Rajendran T, Rajagopal S, Lu KL. Metal-containing molecular rectangles: synthesis and photophysical properties. Coord Chem Rev 2005. [DOI: 10.1016/j.ccr.2004.11.006] [Citation(s) in RCA: 161] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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65
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Reger DL, Brown KJ, Gardinier JR, Smith MD. Syntheses and structural characterizations of rhenium carbonyl complexes of a bitopic ferrocene-linked bis(pyrazolyl)methane ligand. J Organomet Chem 2005. [DOI: 10.1016/j.jorganchem.2004.10.048] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Iengo E, Zangrando E, Baiutti E, Munini F, Alessio E. Synthesis and Structural and Spectroscopic Characterization of New RuII-dmso Precursors with Face-Capping Ligands for Use in Self-Assembly Reactions. Eur J Inorg Chem 2005. [DOI: 10.1002/ejic.200400717] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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67
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Lin R, Yip JHK, Zhang K, Koh LL, Wong KY, Ho KP. Self-Assembly and Molecular Recognition of a Luminescent Gold Rectangle. J Am Chem Soc 2004; 126:15852-69. [PMID: 15571410 DOI: 10.1021/ja0456508] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A luminescent molecular rectangle [Au(4)(micro-PAnP)(2)(micro-bipy)(2)](OTf)(4) (1.(OTf)(4)) (PAnP = 9,10-bis(diphenylphosphino)anthracene, bipy = 4,4'-bipyridine, X = NO(3)(-) or OTf(-)), synthesized from the self-assembly of the molecular "clip" Au(2)(micro-PAnP)(OTf)(2) and bipy, shows a large rectangular cavity of 7.921(3) x 16.76(3) A. The electronic absorption and emission spectroscopy, and electrochemistry of the metallacyclophane, have been studied. The 1(4+) ions are self-assembled into 2D mosaic in the solid state via complementary edge-to-face interactions between the Ph groups. (1)H NMR titrations ratify the 1:1 complexation between 1(4+) and various aromatic molecules. Comparing the structures of the inclusion complexes indicates an induced-fit mechanism operating in the binding. The emission of 1(4+) is quenched upon the guest binding. The binding constants are determined by both (1)H NMR and fluorescence titrations. Solvophobic and ion-dipole effects are shown to be important in stabilizing the inclusion complexes.
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Affiliation(s)
- Ronger Lin
- Department of Chemistry, The National University of Singapore, 10 Kent Ridge Crescent, 119260, Singapore
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Dinolfo PH, Williams ME, Stern CL, Hupp JT. Rhenium-Based Molecular Rectangles as Frameworks for Ligand-Centered Mixed Valency and Optical Electron Transfer. J Am Chem Soc 2004; 126:12989-3001. [PMID: 15469297 DOI: 10.1021/ja0473182] [Citation(s) in RCA: 183] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of six neutral, tetrametallic, molecular rectangles has been synthesized that have the form ([Re(CO)(3)](2)BiBzIm)(2)-mu,mu'-(LL)(2), where BiBzIm is 2,2'-bisbenzimidazolate and LL is a reducible, dipyridyl or diazine ligand. X-ray crystallographic studies of the six show that the rectangle frameworks, as defined by the metal atoms, range in size from 5.7 A x 7.2 A to 5.7 A x 19.8 A. The singly reduced rectangles are members of an unusual category of mixed-valence compounds in which the ligands themselves are the redox centers and interligand electronic communication is controlled by direct ligand orbital overlap rather than by superexchange through the metal ions. Despite nominally identical coordination-defined ligand positioning, the spectrally determined electronic strengths, H(ab)2, vary by roughly 100-fold. As shown by X-ray crystallography and computational modeling, the observed differences largely reflect detailed geometric configurational differences that can either facilitate or frustrate productive direct orbital overlap.
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Affiliation(s)
- Peter H Dinolfo
- Contribution from the Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208-3113, USA
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69
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Han WS, Lee SW. Various forms of linear dipyridyls in discrete rectangles, dinuclear rods, and one-dimensional networks containing (eta5-pentamethylcyclopentadienyl)rhodium(III). Dalton Trans 2004:1656-63. [PMID: 15252617 DOI: 10.1039/b402201g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
[Cp*Rh(eta1-NO3)(eta2-NO3)] (1) reacted with pyrazine (pyz) to give a dinuclear complex [Cp*Rh(eta1-NO3)(mu-pyz)(0.5)]2.CH2Cl2(3.CH2Cl2). Tetranuclear rectangles of the type [Cp*Rh(eta1,mu-X)(mu-L)(0.5)]4(OTf)4(4a: X = N3, L = bpy; 4b: X = N3, L = bpe; 4c: X = NCO, L = bpy) were prepared from [Cp*Rh(H2O)3](OTf)2 (2), a pseudo-halide (Me3SiN3 or Me3SiNCO), and a linear dipyridyl [4,4'-bipyridine (bpy) or trans-1,2-bis(4-pyridyl)ethylene (bpe)] by self-assembly through one-pot synthesis at room temperature. Treating complex with NH4SCN and dipyridyl led to the formation of dinuclear rods, [Cp*Rh(eta1-SCN)3]2(LH2) (5a: L = bpy; 5b: L = bpe), in which two Cp*Rh(eta1-SCN)3 units are connected by the diprotonated dipyridyl (LH2(2+)) through N(+)-H...N hydrogen bonds. Reactions of complex 2 with 1-(trimethylsilyl)imidazole (TMSIm) and dipyridyl (bpy or bpe) also produced another family of dinuclear rods [Cp*Rh(ImH)3]2.L (6a: L = bpy; 6b: L = bpe). Treating 1 and 2 with TMSIm and NH4SCN (in the absence of dipyridyl) generated a 1-D chain [Cp*Rh(ImH)3](NO3)2 (7) and a 1-D helix [Cp*Rh(eta1-SCN)2(eta1-SHCN)].H2O (8.H2O), respectively. The structures of complexes 3.CH2Cl2, 4a.H2O, 4c.2H2O, 5b, 6a, 7 and 8.H2O were determined by X-ray diffraction.
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Affiliation(s)
- Won Seok Han
- Department of Chemistry (BK21), Institute of Basic Science, Sungkyunkwan University, Natural Science Campus, Suwon 440-746, Korea
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Das N, Mukherjee PS, Arif AM, Stang PJ. Facile Self-Assembly of Predesigned Neutral 2D Pt-Macrocycles via a New Class of Rigid Oxygen Donor Linkers. J Am Chem Soc 2003; 125:13950-1. [PMID: 14611218 DOI: 10.1021/ja037788g] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Self-assembly of rigid oxygen donor dicarboxylates such as terephthalate and fumarate with a platinum-containing clip-like acceptor unit afforded neutral macrocyclic rectangles which have been characterized by X-ray single-crystal structure analysis as well as NMR spectroscopy.
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Affiliation(s)
- Neeladri Das
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, UT 84112, USA
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