Premium
The pH‐Dependent Synthesis and Structural Study of Dimer and Cyclic Trimer Complexes of 9‐Methyl‐ or 9‐Ethylhypoxanthine Nucleobases with (η 5 ‐Pentamethylcyclopentadienyl)‐rhodium Aqua Complexes
Author(s) -
Chen Hong,
Olmstead Marilyn M.,
Smith David P.,
Maestre Marcos F.,
Fish Richard H.
Publication year - 1995
Publication title -
angewandte chemie international edition in english
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 0570-0833
DOI - 10.1002/anie.199515141
Subject(s) - trimer , chemistry , dimer , nucleobase , rhodium , ligand (biochemistry) , crystallography , stereochemistry , metal , catalysis , organic chemistry , dna , receptor , biochemistry
η 1 ( N 1 )‐ and η 2 ( N 7 , O 6 )‐coordination of the Rh atoms by 9‐ethylhypoxanthin (9‐EH) is evident in the cyclic trimer 1 (see picture). This is formed from [(C 5 Me 5 RhCl 2 ) 2 ], AgOSO 2 CF 3 , and 9‐EH in water at pH 6.1. An entirely different coordination arises at pH 10.2 for the complex with the ligand 9‐methyl‐hypoxanthin (9‐MH): in the dimer 2 the metal atoms are η 1 ( N 1 )‐coordinated. The formation of dramatically different structures at various pH values could be explained by the changes in the nucleophilicity of the N7, O6, and N1 binding sites.