Reaction of ethylene oxide with the 1,4,8,11-tetraazacyclotetradecanes Me 8 [14]ane L B (diaxial-diequatorial with respect to the methyl substituents at the secondary ring carbons) and

The reactions of two isomers of 3,5,7,7,10,12,14,14-octamethyl-1,4,8,11-tetraazacyclotetradecane (differing in the orientation of the methyl groups on the chiral carbon atoms), designated as L(B) and L(C), with CH(3)I in the ratio of 1:4 resulted in the substitution of the N(4) and N(11) protons by CH(3) groups, forming the dimethyl derivatives L(BZ) and L(CZ), respectively. These ligands, on interaction with nickel(II) acetate tetrahydrate and subsequent addition of lithium perchlorate, produce square-planar yellow [NiL(BZ)][ClO(4)](2) and orange [NiL(C'Z)][ClO(4)](2). These nickel complexes undergo axial ligand addition reactions with NCS(-), Cl(-), Br(-), and I(-) as X(-) to form six-coordinate trans-diisothiocyanato, -dichloro, -dibromo, and -diiodo complexes of formula [NiLX(2)], where L = L(BZ) or L(C'Z), and X = SCN, Cl, Br, or I. All these compounds have been characterized on the basis of analytical, spectroscopic, conductometric, and magnetochemical data. The structures of L(BZ) and two variants of [Ni"L(BZ)"][ClO(4)](2) (crystallizing in the space group P2(1)/n and Pn, respectively; "L(BZ)" symbolizes partially methylated ligand) have been determined by single-crystal X-ray analyses. The antifungal and antibacterial activities of these compounds have been studied against some phytopathogenic fungi and bacteria.

The structure determination of the tetra­aza macrocyclic title compound, C24H46N6, shows that its mol­ecule represents a meso‐isomer; it occupies a special position about the crystallographic inversion centre. The pendent ethyl­cyano arms are oriented above and below the N4 plane and are directed away from the central cavity.

No abstract

Naturally occurring azamacrocyclic metal complexes such as haems, chlorophyll, vitamin B12, and the factor F430 carry pendent ring substituents and axial co-ligands that act as functional components in these important biological systems. Design of related systems with structural features related to their natural counterparts is thus a multifarious challenge. With this in mind, we have recently reported on the characterization and antimicrobial activities of tetraazacyclotetradecanes and their Ni2+ complexes. Here, we present results on modified N-pendent ligands and their Cu2+ complexes: The interaction of two isomers of 3,5,7,7,10,12,14,4,8, LB and LC (differing (2)˚} has been determined by X-ray crystallography. The copper centre is coordinated to an N4 donor set of LCZ1 in a square planar geometry. The antifungal and antibacterial activities of the compounds have been studied against some phyto-pathogenic fungi and bacteria. Generally, the complexes exhibit a more pronounced antimicrobial activity than the parent ligands.