Syntheses, structures and luminescence behaviours of Group 12 metal(II) thiocyanate complexes with a tetradentate Schiff base: Variation in molecular and crystalline architectures with the change of congeneric metal ions
Date
2012
Authors
Das S.
Bhar K.
Chattopadhyay S.
Mitra P.
Smith V.J.
Barbour L.J.
Ghosh B.K.
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
One pentacoordinated mononuclear complex [Zn(L)(NCS)]PF
6 (1), one hexacoordinated 2D coordination polymer {[Cd
2(L)(NCS)
4]·0.24(CH
3OH)}
n (2) and one pentacoordinated 1D polymeric chain [Hg
2(L)(SCN)
4]
n (3) [L = N,N′-(bis(pyridine-2-yl)benzylidene)-1,4- butanediamine] have been synthesized and X-ray crystallographically characterized. Structural analyses revealed interesting variations in the coordination behaviour of the Schiff base (L) from tetradentate chelation to binucleating bis(bidentate) congregation on going from 1 to 2/3. The pseudohalide exhibits terminal N-coordination in 1, both μ
1,3 and μ
1,1 bridges in 2 and terminal S-coordination along with μ
1,1 linkages in 3. In 1/3, each pentacoordinated zinc(II)/mercury(II) centre adopts a distorted trigonal bipyramidal/square pyramidal geometry with a ZnN
5/HgN
2S
3 chromophore, whereas both Cd1 and Cd2 centres in 2 adopt a distorted octahedral geometry with CdN
3S
3 and CdN
6 chromophores, respectively. Weak intermolecular S⋯S and S⋯π interactions with multiple C-H⋯N hydrogen bonds promote the dimensionalities in 1-3. The complexes display intraligand
1(π-π) fluorescence in the solid state and in DMF solutions at room temperature. © 2012 Elsevier Ltd. All rights reserved.
Description
Keywords
Group 12 metal(II), Luminescence, S⋯S/S⋯π interaction, Schiff base, Thiocyanate
Citation
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