Structures of secocubane and nortwistbrendane derivatives
1Department of Chemistry and Biochemistry, University of Maryland, College Park 20742.
Abstract:
(I): 4,7-Dichloro-1-cyano-N-isopropyltetracyclo-[4.2.0.0(2,5).0(3,8)] octane-4-carboxamide, C13H14Cl2N2O, M(r) = 285.17, orthorhombic, Fdd2, a = 34.012 (1), b = 15.791 (2), c = 10.899(1)A, Z = 16, D chi = 1.29 g cm-3, Cu K alpha (lambda = 1.5418 A), mu = 39.2 cm-1, F(000) = 2368, T = 293 K, 1504 reflections with I > 3 sigma(I), R = 0.042. (II): 4,7-Dichloro-N-isopropyl-10-oxo-9-oxatetracyclo [4.4.0.0(2,5).0(3,8)]decane-4-carboxamide, C13H15Cl2NO3, M(r) = 304.17, monoclinic, P2(1)/a, a = 9.902(2), b = 9.381(2), c = 15.174(2) A, beta = 103.25(1) degrees, Z = 4, D chi = 1.47 g cm-3, Cu K alpha (lambda = 1.5418 A), mu = 43.1 cm-1, F(000) = 632, 2107 reflections with I > 3 sigma(I), R = 0.036. (I) represents the first crystallographic example of a secocubane. The nonbonded distances (C4...C7) are 2.742 (5) and 2.717(3) A in (I) and (II). C--C distances in the cage portions of the molecules are typical of cubanes.
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