of 2 are packed by π⋯π and anion ⋯π interactions to form a 2D sheet structure. The complexes show reasonable thermal stabilities and display intraligand π→π ∗ fluorescence in solid state at room temperature. Two mononuclear zinc(II) compounds are isolated and X-ray crystallographically characterized. A subtle change in coordination geometry from square pyramid to octahedral in going from 1 to 2 is
Three dinuclear compounds of the types [Mn-2(L1)(2)(mu-ap)(H2O)(2)](X)(2)center dot MeOH center dot 2H(2)O [X = PF6- (1), BF4- (2)] and [Ni-2(L2)(2)(mu-suc)](PF6)(2) (3) [L1 = N,N'-(bis(pyridin-2-yl)benzylidene)-1,3-Propanediamine, L2 = (bis(pyridin-2-yl)benzylidene)-1,4-butanediamine; ap = adipate dianion and suc = succinate dianion] have been synthesized and X-ray crystallographically characterized. Structural analyses reveal that manganese(II) centers in 1/2 adopt a rare distorted trigonal prismatic geometry whereas nickel(11) centers in 3 are in a distorted octahedral coordination environment each with an MN4O2 chromophore. The ap unit bridges manganese(11) nuclei in 1/2 through its bis(monodentate) mode, whereas the suc connects nickel(11) ions in 3 in bis(bidentate) fashion. Four N atoms of chelated Ll, one bridging O atom of ap and the O atom of coordinated water complete hexacoordination around the metal ions in 1/2. Each nickel(II) center in 3 is surrounded by four N atoms of L2 and two bridging O atoms of suc unit. The dinuclear moities in 1/2 are engaged in intramolecularfintermolecular O-H center dot center dot center dot O, O-H center dot center dot center dot F, C-H center dot center dot center dot N and C-H center dot center dot center dot F hydrogen bonds and pi center dot center dot center dot pi it interactions whereas individual units of 3 self-assemble through C-H center dot center dot center dot F and C-H center dot center dot center dot O hydrogen bonds and C-H center dot center dot center dot pi interactions in cooperative fashions to promote dimensionalities. Variable-temperature magnetic susceptibility measurements of 1-3 in the 2-300 K temperature range reveal weak antiferromagnetic interaction between two metal(II) centers presumably due to long bridging arm of the dicarboxylates. (C) 2014 Elsevier Ltd. All rights reserved.
Rahaman, Sk. Hafijur; Ghosh, Rajarshi; Bose, Doyel, Indian Journal of Chemistry, Section A: Inorganic, Physical, Theoretical and Analytical, 2004, vol. 43, # 9, p. 1901 - 1905