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Complexes of tryptophan dipeptides with the R 2 Sn(IV) 2+ ion (R=Me, Ph): Spectroscopic studies, solution properties and structural implications
Author(s) -
Girasolo M. A.,
Guli G.,
Pellerito L.,
Stocco G. C.
Publication year - 1995
Publication title -
applied organometallic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 71
eISSN - 1099-0739
pISSN - 0268-2605
DOI - 10.1002/aoc.590090307
Subject(s) - chemistry , carboxylate , stereochemistry , crystallography , tryptophan , side chain , nuclear magnetic resonance spectroscopy , trigonal bipyramidal molecular geometry , monomer , deprotonation , amino acid , ion , crystal structure , organic chemistry , biochemistry , polymer
Abstract Tryptophan dipeptides such as L‐tryptophyl‐L‐alanine (H 2 TrpAla), L‐tryptophyl‐L‐tyrosine (H 2 TrpTyr), L‐tryptophyl‐L‐tryptophan (H 2 TrpTrp), along with L‐histidyl‐L‐tyrosine (H 2 HisTyr), were reacted with R 2 SnO (R = Me, Ph) yielding the corresponding complexes. The complexes have been characterized by IR and 119 Sn Mössbauer spectroscopy in the solid state and by 1 H and 13 C NMR in CD 3 OD solutions. Monomeric species were detected, with the tin atom arranged in a pentacoordinated trigonal‐bipyramidal structure. The dipeptides are coordinated via the terminal amino group, deprotonated peptide nitrogen and terminal carboxylate group. No side‐chain appears to be involved in bonding. Determination of rotamer populations for selected compounds was accomplished by vicinal coupling constant analysis and side‐chain orientations are interpreted. In this connection, the potential applications of these compounds as drugs is discussed.