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The preparation, X-ray structure and properties of noncyclic ( 1) and cyclic ( 2) polyaza copper(II) complexes with caged moiety, and copper(II) enhanced hydrolysis of acetonitrile participated in the cyclization of 1 to 2 are reported. The average Cu-N distances of complex 1 and 2 are somewhat shorter than those of square-planar or square-pyramidal complexes of analogue [14]-membered ring copper(II) complexes. These results derived from the squeeze effect of caged moiety of bicyclononan. Reaction of formaldehyde and complex 1 in the presence of base in acetonitrile solution produced complex 2. In this catalytic route, coordination of acetonitrile onto Cu(II) ion, a Lewis acid, of complex 1 makes the electrophilicity of the carbon of nitrile increased. Absorption maximum of the complex 2 is shifted to somewhat shorter wavelength than that of the complex 1. It is supposed to the higher ligand field stabilization energy of complex 2, which has cyclized ligand, comparing that of the complex 1, which has open ligand. These complexes are stable against disproportionation in copper(I) state. [ABSTRACT FROM AUTHOR]

The article discusses the synthesis of macrocyclic nickel(II) complexes bearing N,N-disubstituted amidine pendant arms. Topics include metal-induced C  N Bond Cleavage of the Amidine Group which involves a 14-Membered Tetraaza Macrocycle, the role of amidines in the synthesis of biologically active compounds and the preparation of organic amidines by the reaction of nitriles with amides, amines or ammonia.

In the title compound, C(17)H(25)N(3)O(3), there are intra-molecular hydrogen bonds between an amine H atom and the ep-oxy O atom, and between a dihydro-pyridine ring H atom and the ketone O atom. In the crystal, mol-ecules are linked into a zigzag chain running parallel to the c axis by hydrogen bonds between the hy-droxy group and the ketone O atom. There are also weak C-H⋯O and C-H⋯π inter-actions which link the mol-ecules into sheets lying in the bc plane.

In the title compound, C(22)H(28)O(3), the dihedral angle between the benzene rings is 3.47 (13)° and the five-membered furan ring is essentially planar with a largest deviation of 0.0052 (14) Å. The Csp(2)-Csp(2) bond length between the two benzene rings [1.443 (3) Å] is considerably shorter than those between the benzene and tertiary C atoms [1.538 (3) and 1.530 (3) Å], which are sp(2)-sp(3) hybridized. C-H⋯π inter-actions involving the furan and benzene rings are found in the crystal structure.

In the title compound, C(18)H(17)N(3), the dihedral angle between the dihydropyridine and phenyl rings is 72.57 (5)° and that between the dihydropyridine ring and malononitrile plane is 5.19 (20)°. The C-C bond lengths in the pyridine ring are considerably shorter than those of normal single bonds, indicating that electrons on the dihydropyridine ring, including the non-bonding electrons of the N atom, are delocalized on the ring.

In the title compound, C(13)H(11)ClN(2)O(3), the nine-membered bicycle includes an oxime group having the C=N group in an E configuration. The isoxazole ring is almost planar [r.m.s. deviation = 0.0056 Å]; the dihedral angle between the isoxazole and 4-chloro-phenyl ring is 75.60 (5)°. In the crystal, inter-molecular O-H⋯N(isoxazole) hydrogen bonds give rise to chains running along the b axis.