Cu(I) Dinuclear Complexes with Tripodal Ligands vs Monodentate Donors: Triphenylphosphine, Thiourea, and Pyridine. A 1H NMR Titration Study
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- 作者：Marcello Gennari ; Maurizio Lanfranchi ; Luciano Marchiò ; Maria Angela Pellinghelli ; Matteo Tegoni ; and Roberto Cammi
- 刊名：Inorganic Chemistry
- 出版年：2006
- 出版时间：April 17, 2006
- 年：2006
- 卷：45
- 期：8
- 页码：3456 - 3466
- 全文大小：293K
- 年卷期：v.45,no.8(April 17, 2006)
- ISSN：1520-510X
文摘
Complexes [PPh3Cu(TrMes,Me)] (1), [PPh3Cu(TrMe,o-Py)] (2), and [PPh3Cu(BrMespzo-Py)] (3) (TrMes,Me = hydrotris[1,4-dihydro-3-methyl-4-mesityl-5-thioxo-1,2,4-triazolyl]borate; TrMe,o-Py = hydrotris[1,4-dihydro-4-methyl-3-(2-pyridyl)-5-thioxo-1,2,4-triazolyl]borate; BrMespzo-Py = hydro[bis(thioxotriazolyl)-3-(2-pyridyl)pyrazolyl]borate; PPh3 = triphenylphosphine) were synthesized by the reaction of dinuclear complexes [Cu(TrMes,Me)]2, [Cu(TrMe,o-Py)]2, [Cu(BrMespzo-Py)]2,and PPh3. 1-3 were characterized by 1H, 13C, and 31P NMR spectroscopy and ESI-mass spectrometry. Crystalstructure analyses were performed for 1 and 2. Both complexes crystallize in the triclinic P
space group with themetal in a slightly distorted tetrahedral geometry (S3P coordination) bound by a 
3-S3 ligand and a PPh3 molecule.The solution molecular structures were investigated by means of variable-temperature (210-310 K, CDCl3, 1-2;200-310 K, CD2Cl2, 3) and NOESY NMR spectroscopy. The solution structures of 1-2 are in accordance with theX-ray structures, and the complexes do not exhibit fluxional behavior. On the other hand, 3 is subject to an equilibriumbetween two species with a coalescing temperature of ~260 K. DFT geometry optimizations suggest that themajor species of 3 consists of the BrMespzo-Py ligand bound to Cu(I) in the 3-S2H fashion with two C=S groupsand a [Cu···H-B] interaction. A PPh3 completes the copper coordination (S2HP coordination). The complex [TuCu(TrMes,Me)] (4) (Tu = thiourea) was crystallized using an excess of Tu with respect to [Cu(TrMe,2-Py)]2 (approximatelya 6:1 ratio). The metal adopts a distorted tetrahedral geometry with an overall S3H coordination determined by thebound 3-S2H ligand (two C=S groups and a [B-H···Cu] interaction) and by a Tu. The reactivity of dinuclearcomplexes [Cu(TrMes,Me)]2, [Cu(TrMe,o-Py)]2, and [Cu(BrMespzo-Py)]2 with monodentate ligands was investigated bymeans of NMR titrations with PPh3, Tu. and pyridine (Py), and formation constants for the adducts [DCu(L)] (D =monodentate donor, L = tripodal ligand) were determined.
space group with themetal in a slightly distorted tetrahedral geometry (S3P coordination) bound by a 3-S3 ligand and a PPh3 molecule.The solution molecular structures were investigated by means of variable-temperature (210-310 K, CDCl3, 1-2;200-310 K, CD2Cl2, 3) and NOESY NMR spectroscopy. The solution structures of 1-2 are in accordance with theX-ray structures, and the complexes do not exhibit fluxional behavior. On the other hand, 3 is subject to an equilibriumbetween two species with a coalescing temperature of ~260 K. DFT geometry optimizations suggest that themajor species of 3 consists of the BrMespzo-Py ligand bound to Cu(I) in the 3-S2H fashion with two C=S groupsand a [Cu···H-B] interaction. A PPh3 completes the copper coordination (S2HP coordination). The complex [TuCu(TrMes,Me)] (4) (Tu = thiourea) was crystallized using an excess of Tu with respect to [Cu(TrMe,2-Py)]2 (approximatelya 6:1 ratio). The metal adopts a distorted tetrahedral geometry with an overall S3H coordination determined by thebound 3-S2H ligand (two C=S groups and a [B-H···Cu] interaction) and by a Tu. The reactivity of dinuclearcomplexes [Cu(TrMes,Me)]2, [Cu(TrMe,o-Py)]2, and [Cu(BrMespzo-Py)]2 with monodentate ligands was investigated bymeans of NMR titrations with PPh3, Tu. and pyridine (Py), and formation constants for the adducts [DCu(L)] (D =monodentate donor, L = tripodal ligand) were determined.