Premium
Preparation and Characterization of Dinuclear Nickel(II) Complexes Containing N 3 Ni(μ 1, 3 ‐SO 3 R) 2 (μ‐RCN 4 )NiN 3 Cores: Crystal Structures and Magnetic Properties
Author(s) -
Lach Jochen,
Perlt Eva,
Kirchner Barbara,
Kersting Berthold
Publication year - 2013
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/zaac.201200501
Subject(s) - nickel , chemistry , intramolecular force , crystallography , ligand (biochemistry) , crystal structure , bridging ligand , oxidation state , spectroscopy , metal , stereochemistry , organic chemistry , biochemistry , receptor , physics , quantum mechanics
The preparation and characterization of three new mixed ligand macrocyclic [Ni 2 L2(L′)] + complexes are described, where (L2) 2– represents a supporting macrocyclic hexaaza‐bis(phenylsulfonato) ligand and L′ a tetrazolato ligand. The complexes [Ni 2 (L2)(CN 4 H)]BPh 4 ( 4 ), [Ni 2 (L2)(CN 4 Me)]BPh 4 ( 5 ), and [Ni 2 (L2)(CN 4 Ph)]BPh 4 ( 6 ) were synthesized by H 2 O 2 oxidation of the corresponding [Ni 2 (L1)(CN 4 H)]BPh 4 ( 1 ), [Ni 2 (L1)(CN 4 Me)]BPh 4 ( 2 ), and [Ni 2 (L1)(CN 4 Ph)]BPh 4 ( 3 ) complexes supported by the corresponding hexaaza‐bis(thiophenolate) macrocycle. The compounds were characterized by means of elemental analysis, mass spectrometry, IR, and UV/Vis spectroscopy. The crystal structures of compounds 4 – 6 show that the bridging thiophenolate functions in 1 – 3 are in all cases converted to μ 1, 3 ‐bridging sulfonate groups to generate N 3 Ni(μ 1, 3 ‐SO 3 R) 2 (μ‐RCN 4 )NiN 3 cores. The conversion to the phenylsulfonato groups is accompanied by a drastic increase of the Ni ··· Ni distances from 3.455(1) Å in 1 , 3.425(1) Å in 2 , and 3.443(1) Å [3.450(1) Å] in 3 to 4.2796(5) Å [4.3375(6) Å] in 4 , 4.3402(6) Å in 5 , and 4.2607(4) Å in 6 . Upon oxidation the magnetic properties are affected. In contrast to 1 – 3 , which exhibit an intramolecular ferromagnetic exchange interaction ( S = 2 ground state), the spins of the nickel(II) ( S i = 1) ions in 4 – 6 are antiferromagnetically coupled, the coupling constants J being –1.39 cm –1 ( 4 ), –1.43 cm –1 ( 5 ), and –1.60 cm –1 ( 6 ) ( H = –2 J S 1 S 2 ) to yield a diamagnetic S = 0 ground state. DFT (density functional theory) calculations were carried out to substantiate the experimental results.