Model for the Reduced Schiff Base Intermediate between Amino Acids and Pyridoxal: Copper(II) Complexes of N-(2-Hydroxybenzyl)amino Acids with Nonpolar Side Chains and the Crystal Structures of
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- 作者：Lip Lin Koh ; John O. Ranford ; Ward T. Robinson ; Jan O. Svensson ; Agnes Lay Choo Tan ; and Daqing Wu
- 刊名：Inorganic Chemistry
- 出版年：1996
- 出版时间：October 23, 1996
- 年：1996
- 卷：35
- 期：22
- 页码：6466 - 6472
- 全文大小：201K
- 年卷期：v.35,no.22(October 23, 1996)
- ISSN：1520-510X
文摘
Copper(II) complexes with reduced Schiff base ligands ofamino acids possessing nonpolar side chains withsalicylaldehyde have been synthesized. Ternary complexes withimidazole, 1,10-phenanthroline, and pyridinehave been prepared and characterized forN-(2-hydroxybenzyl)-D,L-alanine.The crystal structures of [(N-(2-hydroxybenzyl)-D,L-alanine)(1,10-phenanthroline)Cu(II)]monohydrate ([Cu(SAla)phen]·H2O) and[(N-(2-hydroxybenzyl)-D,L-alanine)(imidazole)Cu(II)]([Cu(SAla)Him]), have been determined.[Cu(SAla)phen]·H2Ocrystallized in space group P
, with a =8.718(2) Å, b = 10.886(3) Å, c =11.693(2) Å, 
= 71.32(2)
, 
=85.27(2), 
= 70.21(2), and Z = 2.The copper atom is five coordinate, with SAla acting as atridentate ONOchelator through the carboxylato and phenolato oxygens and the aminenitrogen. The remaining donors are providedby the phen nitrogens. [Cu(SAla)Him] crystallized inspace group P21/n, with a= 10.353(1) Å, b = 6.714(1) Å,c = 18.769(2) Å, = 91.71(1), andZ = 4. The copper atom is four coordinate, with SAlaacting as a tridentateONO chelator with the neutral imidazole moiety coordinated throughnitrogen. In both complexes the ligand hastwo chiral centers due to the coordination of the N. Molecularmechanics calculations show that unfavorablesteric interactions would occur in the nonobservedR,R and S,S diastereomers.Compounds prepared have beencharacterized by a range of physicochemical techniques. Thecomplexes may serve as stable models for theintermediates in enzymatic amino acid transformations.
, with a =8.718(2) Å, b = 10.886(3) Å, c =11.693(2) Å, = 71.32(2), =85.27(2), = 70.21(2), and Z = 2.The copper atom is five coordinate, with SAla acting as atridentate ONOchelator through the carboxylato and phenolato oxygens and the aminenitrogen. The remaining donors are providedby the phen nitrogens. [Cu(SAla)Him] crystallized inspace group P21/n, with a= 10.353(1) Å, b = 6.714(1) Å,c = 18.769(2) Å, = 91.71(1), andZ = 4. The copper atom is four coordinate, with SAlaacting as a tridentateONO chelator with the neutral imidazole moiety coordinated throughnitrogen. In both complexes the ligand hastwo chiral centers due to the coordination of the N. Molecularmechanics calculations show that unfavorablesteric interactions would occur in the nonobservedR,R and S,S diastereomers.Compounds prepared have beencharacterized by a range of physicochemical techniques. Thecomplexes may serve as stable models for theintermediates in enzymatic amino acid transformations.