Premium
[Re III (thiourea‐S) 6 ]Cl 3 · 4 H 2 O and [Re III (N‐methylthiourea‐S) 6 ]Cl 3 as Precursors to other Re III Complexes: a Kinetic Study in Aqueous Media. Crystal Structure of [Re III (N‐methylthiourea‐S) 6 ](PF 6 ) 3 · H 2 O
Author(s) -
Otero Lucía,
Benítez Julio,
Gambino Dinorah,
Kremer Eduardo,
Baran Enrique J.,
Mombrú Alvaro,
Suescun Leopoldo,
Mariezcurrena Raúl
Publication year - 1999
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/(sici)1521-3749(199911)625:11<1866::aid-zaac1866>3.0.co;2-l
Subject(s) - thiourea , chemistry , octahedron , ligand (biochemistry) , aqueous solution , crystallography , crystal structure , decomposition , metal , kinetics , stereochemistry , organic chemistry , biochemistry , physics , receptor , quantum mechanics
Capability of [Re III (tu‐S) 6 ]Cl 3 , where tu = thiourea, as a precursor to other Re III complexes by ligand substitution in aqueous medium is studied. For the decomposition of [Re(tu‐S) 6 ]Cl 3 , experiments suggest pseudo first order kinetics and observed rate constants vary from 1.3 × 10 –2 to 9.6 × 10 –2 min –1 in the pH range 2.80–5.04. Experiments in presence of incoming ligand (ethylendiaminetetraacetic acid or diethylentriaminepentaacetic acid) show that ligand substitution is significantly slower than decomposition of the precursor, even when pH and temperature are modified. Similar results were obtained working with [Re III (Metu‐S) 6 ]Cl 3 , where Metu = N‐methylthiourea. Molecular structure of [Re III (Metu‐S) 6 ](PF 6 ) 3 · H 2 O was determined by single crystal X‐ray diffractometry. The coordination polyhedron around the Re ion is a distorted octahedron. The six methylthiourea ligands are bonded to the metal through the sulfur atoms [bond lengths range from 2.409(2) to 2.451(2) Å].