Springer Online Journal Archives 1860-2000
Chemistry and Pharmacology
Abstract A bridged high-spin complex,bis-[Ni(II)(rac-5,5,7,l2,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane)]-2,5-pyridinedicarboxylate diperchlorate monohydrate has been obtained by reaction of [Ni(II)(rac-5,5,7, 12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane)](ClO4)2 and 2,5-pyridinedicarboxylic acid in aqueousalkaline (NH4OH) medium. C39H77Cl2N9Ni2O13, chemical formula weight 1068.42, orthorhombic, P212121, a = 11 .423(3) Å,b = 14.770(6) Å, c = 31.608(7) Å,α = β = γ =90.00°, V = 5333(3) Å3, Z = 4, Dcalc = 1.331 g cm-3, μcalc = 0.869 mm-1, F(000) = 2272, T = 293(2), R = 0.0870 for 2686 observed reflections [I 〉 2σ(I)]. The complexincludes two folded [Ni(rac- Me6aneN4)]2+ units havingopposite diastereomeric configuration. They are bridged through a dianion of2,5-pyridinedicarboxylic acid, with one Ni-atom coordinated to the O-atom ofthe 2-carboxylic group and the pyridine N-atom (forming a 5-membered chelatering), and with the second Ni-atom coordinated to both O-atoms of the 5-carboxylic group (forming a 4-membered chelate ring). Hydrogen bonding involving macrocyclic NH groups, both 2- and 5-carboxylic groups, perchlorate anions and water molecules gives rise to the formation of an infinite supramolecular network in the title compound's crystals.
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