The complexes [Pd(phen)(aa)]Cl.3H2O, where phen is 1,10-phenanthroline and aa is the anion of glycine (gly), .DL-alanine (ala), DL-serine (ser) or DL-asparagine (asn), were synthesized and characterized by spectroscop...The complexes [Pd(phen)(aa)]Cl.3H2O, where phen is 1,10-phenanthroline and aa 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, 1H-1H COSY and 1H-13C COSY techniques. In the 1H 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 shifts as compared to those of ring A. The probable structures were described on the basis of a metal-non-bonded hydrogen interaction, trons effect and ligand-ligand interaction. There may exist three conformation isomers in the [Pd(phen)(asn)]Cl.3H2O complex at room temperature. The preferred conformation isomer is about 75% in terms of the relative peak areas in the a-CH part of the spectra.展开更多
基金Project supported by the National Natural Science Foundation of China,Doctoral Foundation ofInstitution of High Education and Research Foundation of the State Key Laboratory of Coordination Chemistry,Nanjing University.
文摘The complexes [Pd(phen)(aa)]Cl.3H2O, where phen is 1,10-phenanthroline and aa 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, 1H-1H COSY and 1H-13C COSY techniques. In the 1H 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 shifts as compared to those of ring A. The probable structures were described on the basis of a metal-non-bonded hydrogen interaction, trons effect and ligand-ligand interaction. There may exist three conformation isomers in the [Pd(phen)(asn)]Cl.3H2O complex at room temperature. The preferred conformation isomer is about 75% in terms of the relative peak areas in the a-CH part of the spectra.
