Premium
Synthesis, Characterization, and Magnetic Behaviour of Dinuclear Nickel(II) Complexes of N,N′‐Substituted Dithiooxamides derived from α‐Amino Acids
Author(s) -
Castiñeiras A.,
Vidal M. C. F.,
Romero J.,
Sáez R.,
Matilla A.,
Niclós J.,
Tercero J. M.
Publication year - 2001
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 - 10.1002/1521-3749(200107)627:7<1553::aid-zaac1553>3.0.co;2-7
Subject(s) - chemistry , nickel , crystallography , magnetic susceptibility , octahedron , dimer , paramagnetism , crystal structure , magnetic moment , stereochemistry , infrared spectroscopy , physics , organic chemistry , quantum mechanics , condensed matter physics
New dinuclear complexes of the types [Ni 2 (L)(H 2 O) 2 ] and [Ni 2 (L)(H 2 O) 6 ] [H 4 L = N,N′‐bis(carboxymethyl) dithiooxamide (H 4 GLYDTO), N,N′‐bis(1‐carboxyethyl) dithiooxamide (H 4 ALADTO), N,N′‐bis(1‐carboxy‐2‐methylpropyl) dithiooxamide (H 4 VALDTO) and N,N′‐bis(1‐carboxy‐3‐methylbutyl) dithiooxamide (H 4 LEUDTO)] have been prepared and characterized by IR and electronic absorption spectroscopy, and the structure of [Ni 2 (ALADTO)(H 2 O) 6 ] crystals has been determined by single crystal X‐ray analysis. This compound is composed of discrete dinuclear units in which two Ni II atoms with NO 4 S kernels are linked by a single [ALADTO] 4– group that coordinates through its carboxylato oxygen, amino nitrogen and thiolato sulphur atoms. In each dimer unit the two nickel(II) ions in distorted octahedral coordination are separated by 5.863(2) Å The temperature dependence of the magnetic susceptibility of the new compounds was measured over the range 2 to 300 K. In the complexes of [GLYDTO] 4– and [ALADTO] 4– the two Ni atoms are antiferromagnetically coupled, with J = –23.51(4) and –20.95(8) cm –1 , respectively. By constrast, [Ni 2 (VALDTO)(H 2 O) 2 ], [Ni 2 (VALDTO)(H 2 O) 6 ] and [Ni 2 (LEUDTO)(H 2 O) 2 ] remain paramagnetic down to 2 K, with magnetic moment values between 2.8 and 3.3 M.B.