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The structural characterization of some palladium(II) complexes of 1,10‐phenanthroline and amino acids by NMR spectroscopy
Author(s) -
Ye BaoHui,
Zeng TianXian,
Ji LiangNian
Publication year - 1995
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.19950130304
Subject(s) - chemistry , ligand (biochemistry) , phenanthroline , chemical shift , proton nmr , stereochemistry , alanine , ring (chemistry) , palladium , nuclear magnetic resonance spectroscopy , nmr spectra database , crystallography , hydrogen bond , two dimensional nuclear magnetic resonance spectroscopy , molecule , amino acid , spectral line , organic chemistry , receptor , catalysis , biochemistry , physics , astronomy
The complexes [Pd(phen)(aa)]Cl·3H 2 O, where phen is 1,10‐phenanthroline and as is the anion of glycine (gly), DL ‐alanine (ala), DL‐ serine (ser) or DL ‐asparagine (asn), were synthesized and characterized by spectroscopies. The NMR signals were assigned completely on the basis of the double irradiation, 1 H‐ 1 H COSY and 1 H‐ 13 C COSY techniques. In the 1 H NMR spectra of phen in the complexes, the signals of 2‐H and 9‐H show upfield shifts 0.8–1 ppm, while the signals of 4‐H and 3‐H show downfield shifts or almost no shift, as compared to the free phen ligand, and the signal of 4‐H appears in the lowest field. The signals of ring B which is trans to the carboxyl group show significant upfield shirts as compared to those of ring A. The probable structures were described on the basis of a metal‐non‐bonded hydrogen interaction, trans effect and ligand‐ligand interaction. There may exist three conformation isomers in the [Pd(phen)(asn)]Cl·3H 2 O complex at room temperature. The preferred conformation isomer is about 75% in terms of the relative peak areas in the α‐CH part of the spectra.