A (2‐amino‐2‐methylpropanedioato)(optically active cyclen)cobalt(III) complex

cis-(SSSR)-fll-[ (R)-2-Amino-2-methylmalonato] (2R,5R,8R, 11R-2,5,8,11-tetraethyl1,4,7,10tetraazacyclododecane)cobalt(III) perchlorate 2.5hydrate, [Co(C4HsNO4)(CI6H36N4)]C104.2.5H20, M r = 619.00, triclinic, PI , a = 10.455 (5), b = 31.715(15), c 1 0 . 4 9 2 ( 7 ) A , a = 1 1 0 . 5 0 ( 5 ) , f l= 116.74(5), y = 8 0 . 3 6 ( 5 ) °, U = 2 9 1 0 ( 3 ) A 3, Z = 4 , D m = 1.410, D x = 1.415 Mg m -3, 2(Mo Ka) = 0.71073 A, l z = 0 . 7 4 m m -1, F (000)= 1316, T = 296 K, final R = 0.068 for 7646 unique reflections with IFol >3cr(IFol ). The geometries of the four independent molecules in the unit cell are essentially the same. In each octahedral molecule, the Co Ill ion is surrounded by four N of the macrocycle, and by N and O atoms of pro-R carboxylate in the amino acid. The * Part 9 of the series Metal Complexes ofChiral Cyclen. Part 8: Tsuboyama, Takishima, Sakurai & Tsuboyama (1987). "t" To whom correspondence should be addressed. 0108-2701/89/040669-04503.00 uncoordinated carboxyl group forms an intramolecular hydrogen bond to one of the N atoms in the macrocyclic ligand, in molecule 1 [N(1)-H .... O(17)2:2.98 (1) A , / N ( 1 ) H . . . O ( 1 7 ) 2 : 1 5 9 (12)°]. Experimental. The crystal was obtained from the same reaction product as the monoclinic one whose structure had already been reported (Tsuboyama, Takishima, Sakurai & Tsuboyama, 1987). The density was measured by flotation in CC14-benzene. Details of data collection and structure refinement are given in Table 1. Structure solved by direct methods with MULTAN78 (Main, Fiske, Hull, Lessinger, Germain, Declercq & Woolfson, 1978). Calculations performed using the program system UNICS-III (Sakurai & Kobayashi, 1979) on a FACOM M-780. The four independent molecules are labelled 1, 2, 3 and 4. The molecular geometries of these are almost identical to that of the monoclinic crystal. The H atom attached to © 1989 International Union of Crystallography 670 [Co(C4HsNO4)(C 16H36N4)] CIO4. 2. 5H20 Table 1. Experimental details Crystal Orange-red, pillar, 0.24 x 0.36 x 0.40 mm Diffraetometer used Rigaku A F C automated four-circle Monoehromator Graphite Unit cell 16 reflections, 25.0 > 20 > 20.0 ° Data correction applied Lorentz and polarization, not absorption Mode to, o7-20 (20 > 30 °) Scan rate (deg min -~) 4.0 Scan ranges of h, k, l -13--,13, ---4 l-L4_ 1, 0--13 Standards 300, 0 16 0, 293, 007 e . t . . . No. of reflections between 150, no mtenmy variation standards 20range (o) 55 Reflections observed 11 812 No. of unobs, reflections 6489 [criterion: IFol > 3o( IFol )] Parameters refined 1498 R " 0.068 wR 0.073 Maximum shift/e.s.d. 0.35 * Max. height in final map (e A -3 ) 0.7 * Except for disordered ethyl groups and anions.