Structural, magnetic, high-frequency and high-field EPR investigation of double-stranded heterometallic [{Ni(en)2}2(micro-NCS)4Cd(NCS)2](n).nCH3CN polymer self-assembled from cadmium oxide, nickel thiocyanate and ethylenediamine.
A novel heterometallic 1D coordination polymer [{Ni(en)2}2(micro-NCS)4Cd(NCS)2](n) x nCH3CN (en = ethylenediamine) has been prepared using the self-assembly process in a one-pot reaction of cadmium oxide, nickel and ammonium thiocyanates with an acetonitrile solution of ethylenediamine. The complex consists of an uncommon cis-Cd(SCN)4(NCS)2(4-) fragment and a rare combination of cis-Ni(en)2(2+) and trans-Ni(en)2(2+) building blocks linked by micro(1,3)-NCS bridges into a double-stranded zigzag chain structure. Each chain is comprised of [Ni2Cd2(micro-NCS-N,S)4)] macrocycles with chair-like and rectangular-like shapes arrayed alternately. The shortest intrachain CdCd separations are 9.535(1) and 10.868(2) A, while the nearest NiNi distances are 5.418(1) and 6.612(2) A. A network of weak N-HS hydrogen bonds, involving the terminal NCS ligands and NH2-groups of en, links the infinite chains and results in the formation of an extended supramolecular three-dimensional framework. Variable-temperature (1.8-300 K) magnetic susceptibilities show a slight change of the micro(B) value at low temperature, indicative of weak antiferromagnetic interactions (J = 1.55 cm-1) between magnetic canters. High-field, high-frequency (100-400 GHz) EPR spectra were simulated using S = 1 ground state for separate Ni2+ ions with the spin Hamiltonian parameters g = 2.165, D = 0.45 cm-1 and E = 0.03 cm(-1). According to DFT calculations, the D and E parameters are -0.35 cm(-1) and 0.049 cm-1 for the cis arrangement of Ni2+ and 0.58 cm(-1) and 0.012 cm(-1) for trans.
Nesterova
Oksana V
OV
Department of Inorganic Chemistry, National Taras Shevchenko University, Volodymyrska str. 64, Kyiv, 01033, Ukraine. nesterova@univ.kiev.ua
Petrusenko
Svitlana R
SR
Kokozay
Vladimir N
VN
Skelton
Brian W
BW
Jezierska
Julia
J
Linert
Wolfgang
W
Ozarowski
Andrew
A
D019187:Cadmium Compounds / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004578:Electron Spin Resonance Spectroscopy; D005029:Ethylenediamines / Q000737:chemistry*; D006860:Hydrogen Bonding; D007536:Isomerism; D008280:Magnetics; D008958:Models, Molecular; D008968:Molecular Conformation; D010087:Oxides / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013861:Thiocyanates / Q000737:chemistry*
D019187:Cadmium Compounds; D005029:Ethylenediamines; D010087:Oxides; D011108:Polymers; D013861:Thiocyanates; C121141:nickel thiocyanate; C029663:cadmium oxide; C031234:ethylenediamine