| Abstract
| - Copper(II) and VIVO complexes of an open chain(1:2) Schiff-base ligand (H2L1), derived by thetemplatecondensation of diaminomaleonitrile (DMN) and salicylaldehyde, anddicopper(II) complexes of (2:2) macrocyclicSchiff-base ligands derived by template condensation of diformylphenolsand diaminomaleonitrile, have beensynthesized and studied. Structures have been established for thefirst time for mononuclear Cu(II) andVIVOderivatives of the open chain ligand H2L1 (1:2), adinuclear macrocyclic Cu(II) complex derived from a2:2macrocyclic ligand (H2M1), and the half-condensed 1:1salicylaldehyde ligand (H2L2). [Cu(L1)](1) (L1 =C18H10N4O2)crystallized in the monoclinic system, space groupP21/n (No. 14), with a =11.753(6) Å, b =7.708(5) Å, c = 16.820(1) Å, and Z= 4. [VO(L1)(DMSO] (2) crystallized inthe orthorhombic system, spacegroup Pbca (No. 61), with a = 22.534(9)Å, b = 23.31(1) Å, c = 7.694(5)Å, and Z = 8. H2L2(C18H8N4O)(3)crystallized in the monoclinic system, space groupP21/c (No. 14), with a =13.004(6) Å, b = 11.441(7) Å, c=7.030(4) Å, and Z = 4.[Cu2(M3)](CH3COCH3)(4) (M3 =C32H24N8O4)crystallized in the monoclinic system,space group C2/c (No. 15), with a =38.33(2) Å, b = 8.059(4) Å, c =22.67(2) Å, and Z = 8.[Cu(L3)(DMSO)](5) (L3 =C20H14N2O4)crystallized in the triclinic system, space group P1̄(No. 2), with a = 10.236(4) Å, b=13.514(4) Å, c = 9.655(4) Å, and Z= 2. 4 results from the unique addition of twoacetone molecules to twoimine sites in[Cu2(M1)](ClO4)2 (M1= 2:2 macrocyclic ligand derived from template condensation of DMNand2,6-diformyl-4-methylphenol). 4 has extremely smallCu−OPh−Cu bridge angles (92.0, 92.8°), well belowtheexpected lower limit for antiferromagnetic behavior, but is stillantiferromagnetically coupled (−2J = 25.2cm-1).This behavior is associated with a possible antiferromagneticexchange term that involves the conjugated frameworkof the macrocyclic ligand itself. The ligand L3 in 5results from hydrolysis of M1 on recrystallization of[Cu2(M1)](ClO4)2 from undrieddimethyl sulfoxide.
- Copper(II) and vanadium(IV) complexes of openchain and macrocyclic Schiff-base ligands derived fromdiaminomaleonitrile are described. Structures are reported forfive complexes, including a unique neutral, macrocyclicdicopper(II) complex resulting from addition of two acetonemolecules to two imine groups in a precursor, macrocyclicdicopper(II) complex. Magnetic studies indicate weakantiferromagnetic coupling (−2J = 25.2cm-1) for this compound, despite very smallCu−OPh−Cu angles (92.0,92.8°).
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