Comparison of Heteronuclear Coupling Constants for Isostructural Nitrogen Coordination Compounds of 111/113Cd and 199Hg
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- 作者：Deborah C. Bebout ; Sarah W. Stokes ; and Raymond J. Butcher
- 刊名：Inorganic Chemistry
- 出版年：1999
- 出版时间：March 22, 1999
- 年：1999
- 卷：38
- 期：6
- 页码：1126 - 1133
- 全文大小：171K
- 年卷期：v.38,no.6(March 22, 1999)
- ISSN：1520-510X
文摘
The complexation of Cd(II) by the tripodal ligand tris[(2-pyridyl)methyl]amine and dipodal ligand bis[(2-pyridyl)methyl]amine was investigated by solution-state NMR and X-ray crystallography. Cadmium coordinationcompounds exhibiting rarely observed solution-state NMR 1H-111/113Cd satellites were characterized. The eight-coordinate complex [Cd(TMPA)2](ClO4)2·toluene (1) crystallizes in the triclinic space group P1 with a = 9.629(2) Å, b = 11.020(2) Å, c = 11.641(2) Å, 
chars/alpha.gif" BORDER=0> = 114.069(13)
, chars/beta2.gif" BORDER=0 ALIGN="middle"> = 97.492(13), chars/gamma.gif" BORDER=0 > = 91.034(14), and Z = 1. Theaverage Cd-Namine distance is 2.53(4) Å and the average Cd-Npyridyl distance is 2.54(6) Å. The complex [Cd(BMPA)(NCCH3)(OH2)(OClO3)][Cd(BMPA)2](ClO4)3·(CH3CN) (2) crystallizes in the triclinic space group P
cr.gif">with a = 10.446(2) Å, b = 16.653(3) Å, c = 17.736(3) Å, chars/alpha.gif" BORDER=0> = 62.479(9), chars/beta2.gif" BORDER=0 ALIGN="middle"> = 80.606(14), chars/gamma.gif" BORDER=0 > = 84.66(2), andZ = 2. In the pseudo-octahedral monocation, the nitrogen-containing ligands occupy equatorial positions withCd-N distances of 2.321(8), 2.283(7), and 2.263(8) Å for the amine, pyridyl (average) and acetonitrile nitrogens,respectively. Significant axial interactions occur with Cd-O bond distances of 2.313(7) Å (water) and 2.478(7)Å (perchlorate). In the pseudo-trigonal prismatic dication, the average Cd-Namine distances is 2.395(5) Å and theaverage Cd-Npyridyl distance is 2.362(8) Å. The solid-state structures and solution-state NMR trends were verysimilar to recently reported isovalent complexes of Hg(II), providing an exceptional opportunity to compare couplingconstants of coordination compounds. Implications for the use of 111/113Cd and 199Hg NMR as metallobioprobesare discussed.
chars/alpha.gif" BORDER=0> = 114.069(13), chars/beta2.gif" BORDER=0 ALIGN="middle"> = 97.492(13), chars/gamma.gif" BORDER=0 > = 91.034(14), and Z = 1. Theaverage Cd-Namine distance is 2.53(4) Å and the average Cd-Npyridyl distance is 2.54(6) Å. The complex [Cd(BMPA)(NCCH3)(OH2)(OClO3)][Cd(BMPA)2](ClO4)3·(CH3CN) (2) crystallizes in the triclinic space group Pcr.gif">with a = 10.446(2) Å, b = 16.653(3) Å, c = 17.736(3) Å, chars/alpha.gif" BORDER=0> = 62.479(9), chars/beta2.gif" BORDER=0 ALIGN="middle"> = 80.606(14), chars/gamma.gif" BORDER=0 > = 84.66(2), andZ = 2. In the pseudo-octahedral monocation, the nitrogen-containing ligands occupy equatorial positions withCd-N distances of 2.321(8), 2.283(7), and 2.263(8) Å for the amine, pyridyl (average) and acetonitrile nitrogens,respectively. Significant axial interactions occur with Cd-O bond distances of 2.313(7) Å (water) and 2.478(7)Å (perchlorate). In the pseudo-trigonal prismatic dication, the average Cd-Namine distances is 2.395(5) Å and theaverage Cd-Npyridyl distance is 2.362(8) Å. The solid-state structures and solution-state NMR trends were verysimilar to recently reported isovalent complexes of Hg(II), providing an exceptional opportunity to compare couplingconstants of coordination compounds. Implications for the use of 111/113Cd and 199Hg NMR as metallobioprobesare discussed.