SYNTHESIS AND SPECTROSCOPIC CHARACTERIZATION OF 5-COORDINATE COMPLEXES OF NI2-3-MACROCYCLES AND SALICYLALDIMINATES - CRYSTAL-STRUCTURE OF [NI(9-ME-N-3-MC)(OC6H4CH=NC6H5-O)](CLO4) 2,4,4,9-TETRAMETHYL-1,5,9-TRIAZACYCLODODEC-1-ENE)( BASED ON N)

Five-coordinate nickel(II) complexes of the type [Ni(N-3-macrocycle) ( OC6H4CH=NR-o)](+) ycle=2,4,4-trimethyl-1,5,9-triazacyclododec-1-ene, N -3-mc, or its 9-methyl derivative, 9-Me-N-3-mc) have been prepared by reaction between [{Ni-3(N-3-macrocycle) (mu-OH)}(2)](+) and the approp riate arylsalicylaldimine. An X-ray diffraction study carried out with the complex [Ni(9-Me-N-3-mc)(OC6H4CH=NC6H5-o)](ClO4) has established that the Ni atom presents a square pyramidal coordination and is displ aced 0.30 A out of the basal plane towards the apical N1 atom (a=8.552 (2), b=33.398(3), c=9.630(3) Angstrom, beta=91.67(1)degrees, monoclini c, space group P2(1)/a, V=2749(1) Angstrom(3), Z=4, D-calc=1.40 g cm(- 3), R=0.058, R(w)=0.066). These paramagnetic species have been studied by H-1 NMR, The characteristic pattern of N-3-mc and 9-Me-N-3-mc has been established and the specific assigment of salicylaldimine resonan ces has been achieved by NOE measurements. The solution electronic spe ctra of the complexes are also suggestive of five-coordinate geometry in solution.