TRANSITION-METAL COMPOUNDS OF THE TRIDENTATE PYRAZOLE SUBSTITUTED AMINE LIGAND BIS(2-(3,5-DIMETHYL-1-PYRAZOLYL)ETHYL)ETHYLAMINE (DDAE) - X-RAY STRUCTURES OF [CO(DDAE)(NO3)2], [CU(DDAE)(NO3)(H2O)](NO3) AND [CU(DDAE)(CL)2].C2H5OH

Six new compounds of the ligand bis(2-(3,5-dimethyl-1-pyrazolyl)ethyl) ethylamine (ddae), viz. [Co(ddae)(NO3)2], [Ni(ddae)(NO3)2], [Cu(ddae)( Cl)2].(C2H5OH), [Cu(ddae)(NO3)(H2O)](NO3), [Ni(ddae)(H2O)(BF4)2] and [ Cu(ddae)(F)(BF4)] are described. These transition metal compounds are mononuclear. In all cases ddae acts as a tridentate ligand. The cobalt and nickel nitrates are isomorphous, otherwise these compounds all ha ve different structures. The compound [Cu(ddae)Cl2].C2H5OH crystallize s in the monoclinic space group P2(1)/c with a = 8.327(1), b = 14.782( 2), c = 18.654(3) angstrom, beta = 96.53(1)-degrees and Z = 4. The str ucture was solved by heavy-atom methods and refined by least-squares m ethods to a residual R of 0.048 (R(w) = 0.081) for 2787 significant re flections. The asymmetric unit comprises the whole formula unit. The s urrounding geometry of the Cu(II) ion is distorted square-pyramidal wi th the two pyrazole nitrogens (Cu-N distances 1.984(4) and 1.999(4) an gstrom) and the two chloride ions (Cu-Cl distances 2.322(2) and 2.400( 2) angstrom) in a square and the amine nitrogen (Cu-N distance 2.181(4 ) angstrom) at the apex. The ligand is coordinated in a mer geometry. The ethanol molecule is hydrogen bonded to one of the chloride ions wi th a Cl-O distance of 3.24(1) angstrom. The compound [Cu(ddae)(NO3)(H2 O)](NO3) crystallizes in the orthorhombic space group Pna2(1) with a = 24.984(5), b = 10.798(2), c = 8.466(3)angstrom and Z = 4. The structu re was solved by heavy-atom methods and refined by least-squares metho ds to a residual R of 0.048 (R(w) = 0.069) for 960 significant reflect ions. The asymmetric unit comprises the whole formula unit. The Cu(II) ion is in a distorted square-pyramidal environment of the two pyrazol e nitrogens at 2.00(1) and 2.01(1) angstrom, a water oxygen atom at 1. 938(9) angstrom, and an oxygen atom of one of the nitrate ions at 2.00 (1) angstrom in a square, and the amine nitrogen at 2.34(1) angstrom a t the apex. The ligand is folded and coordinated in a fac geometry. If the nitrate ion was regarded as bidentate-coordinate with the rather too long Cu-O distance of 2.63(1) angstrom, then the copper ion would be in a strongly distorted octahedral environment. The water molecule is hydrogen bonded to the non-coordinated nitrate ion in two different , symmetry related, positions, with O-O distances of 2.74(1) and 2.81( 2) A, in such a way that the complex cations are linked together in a chain. The compound [Co(ddae)(NO3)2] crystallizes in the monoclinic sp ace group P2(1)/c with a = 16.351(3), b = 15.708(2), c = 8.484(1) angs trom, beta = 104.78(1)-degrees and Z = 4. The structure was solved by heavy-atom methods and refined by least-squares methods to a residual R of 0.077 (R(w) = 0.065) for 1502 significant reflections. The asymme tric unit comprises the whole formula unit. The surrounding geometry o f the Co(II) ion is distorted octahedral, with the ligand folded in a fac geometry with the N(amine) at 2.209(9) A and the N(pyrazoles) at 2 .030(10) and 2.112(9) angstrom. One of the nitrate ions is monodentate with Co-O of 2.060(8), the other nitrate is quite symmetrically biden tate coordinated to the cobalt ion with Co-O distances of 2.172(8) and 2.216(8) angstrom.