Hybrid (Te, N) and (N, Te, N) ligands having pyrrolidine ring and their palladium(II) and mercury(II) complexes: synthesis and crystal structures
摘要:
Reactions of (2-choroethyl)pyrrolidine hydrochloride with ArTe- or Te2- generated in situ by borohydride reduction of Ar2Te2 or elemental tellurium give N-{2-(4-methoxyphenyltelluro)ethyl}pyrrolidine (L-1) or bis{2-(pyrrolidine-N-yl)ethyl} telluride (L-2), respectively, as viscous liquids, which are characterized by H-1- and C-13 {H-1}-NMR spectroscopy. The potentially bidentate hybrid organotellurium ligand (L-1) reacts with HgBr2 and Na2PdCl4 to give complexes [HgBr2.L-1] (1) and [PdCl2.L-1] (2) respectively. The potentially tridentate ligand (L-2) also forms a complex [HgBr2.L-2] (3). All three complexes give characteristic H-1- and C-13{H-1}-NMR spectra, although the deshielding of carbon atoms linked to Te/N as well as protons attached to them is small in the case of both Hg complexes. The single crystal structures of 1-3 have been solved. In 1 and 2 the ligand L-1 coordinates via Te and N both with metal indicating that the pyrrolidine N has good ligating strength. The Pd-Te and Hg-Te bond lengths are 2.4781(3) and 2.747(1) Angstrom, respectively. The Pd-Cl trans to Te (2.3915(7) Angstrom) is longer than other Pd-Cl bond length. There are two independent molecules in the asymmetric unit of 3 that have essentially the same bidentate molecular structures. There is no evidence of significant intermolecular Hg-Br bonding. The Hg-Te bond in 3 (ave. 2.686(2) Angstrom) is shorter than in 1. The potentially tridentate ligand L 2 in complex 3 coordinates only as a bidentate donor. The molecular weights of 1 and 2 are close to double the formula weight indicating strong molecular association in solution. Te-C(alkyl) is somewhat longer than Te-C(aryl) for complexes 1 and 2. (C) 2003 Elsevier B.V. All rights reserved.
Hybrid (Te, N) and (N, Te, N) ligands having pyrrolidine ring and their palladium(II) and mercury(II) complexes: synthesis and crystal structures
作者:Garima Singh、Ajai K. Singh、Pankaj Sharma、John E. Drake、Michael B. Hursthouse、Mark E. Light
DOI:10.1016/j.jorganchem.2003.08.024
日期:2003.12
Reactions of (2-choroethyl)pyrrolidine hydrochloride with ArTe- or Te2- generated in situ by borohydride reduction of Ar2Te2 or elemental tellurium give N-2-(4-methoxyphenyltelluro)ethyl}pyrrolidine (L-1) or bis2-(pyrrolidine-N-yl)ethyl} telluride (L-2), respectively, as viscous liquids, which are characterized by H-1- and C-13 H-1}-NMR spectroscopy. The potentially bidentate hybrid organotellurium ligand (L-1) reacts with HgBr2 and Na2PdCl4 to give complexes [HgBr2.L-1] (1) and [PdCl2.L-1] (2) respectively. The potentially tridentate ligand (L-2) also forms a complex [HgBr2.L-2] (3). All three complexes give characteristic H-1- and C-13H-1}-NMR spectra, although the deshielding of carbon atoms linked to Te/N as well as protons attached to them is small in the case of both Hg complexes. The single crystal structures of 1-3 have been solved. In 1 and 2 the ligand L-1 coordinates via Te and N both with metal indicating that the pyrrolidine N has good ligating strength. The Pd-Te and Hg-Te bond lengths are 2.4781(3) and 2.747(1) Angstrom, respectively. The Pd-Cl trans to Te (2.3915(7) Angstrom) is longer than other Pd-Cl bond length. There are two independent molecules in the asymmetric unit of 3 that have essentially the same bidentate molecular structures. There is no evidence of significant intermolecular Hg-Br bonding. The Hg-Te bond in 3 (ave. 2.686(2) Angstrom) is shorter than in 1. The potentially tridentate ligand L 2 in complex 3 coordinates only as a bidentate donor. The molecular weights of 1 and 2 are close to double the formula weight indicating strong molecular association in solution. Te-C(alkyl) is somewhat longer than Te-C(aryl) for complexes 1 and 2. (C) 2003 Elsevier B.V. All rights reserved.