ABSTRACT
The title compound, meso-1,2-bis(methyldiazenyl)-1,2-diphenylethane, C16H18N4, is arranged in a disordered manner around an inversion point. The N-N atom distances in the azo group of 1.192 (8) and 1.195 (8) A, and the C-C atom distances in the ethylene moiety at 1.512 (8) and 1.503 (8) A in the two models [refined to 51.7 (6) and 48.3 (6)% occupancies] were not significantly different.
ABSTRACT
The synthesis of ReCl(H(2))(AsMePh(2))(4) is reported and verified on the basis of (1)H NMR and FAB-MS. The minimum T(1) time for the metal-bonded hydrogen atoms was determined to be 44 ms (-78 degrees C) and 89 (-48 degrees C) ms at 200 and 400 MHz, respectively. From this minimum T(1) time, and, allowing for contributions from other nuclei to the relaxation, a metal-bonded H to H atom distance of 1.57 A can be assessed. The complex is reversibly oxidized at a potential E(1/2)(ox) = +0.07 V. The J(HD) coupling in the related ReCl(HD)(AsMePh(2))(4) compound was at 3.3 Hz. These data for ReCl(H(2))(AsMePh(2))(4) suggest that this molecule contains classical hydrides, and interpretations on T(1) and X-ray data published previously for ReCl(H(2))(PMePh(2))(4) suggest that this molecule contains a very long metal-bonded H-H interaction of 1.39 A. Theoretical calculations on model compounds ReCl(H(2))(XR(3))(4) (X = P, As; R = H, Me) give virtually identical average d(H-H) values of 1.5 (XH(3)) and 1.63 (XMe(3)) A.
ABSTRACT
The structure of the cation in [Cr(C(12)H(8)N(2))(3)](ClO(4))(3).H(2)O consists of the Cr atom bonded to the N atoms of the three 1,10-phenanthroline (phen) ligands, resulting in a distorted octahedral arrangement with the six Cr-N distances ranging from 2.040 (4) to 2.055 (4) A. One of the perchlorate anions is disordered and is located around two special positions.
ABSTRACT
The title structure, C14H19ClO5, consists of an allene substituted with a Cl atom at one end joined at the other end to a D-galactopyranose ring bearing two fused isopropylidene groups.
Subject(s)
Galactose/analogs & derivatives , Crystallography, X-Ray , Galactose/chemistry , Molecular Conformation , Molecular StructureABSTRACT
Two unrelated molecules of the title compound, ethyl 1-(5-deoxy-1,2-O-isopropylidene-alpha-D-xylofuranos-5-C- yl)-1,2,3-triazole-5-carboxylate, C13H19N3O6, that are not linked by hydrogen bonding, comprise the asymmetric unit. There are no unusual bond lengths or angles. The two molecules differ in the degree of rotation around the methylene C atom that joins the triazole ring to the sugar part of the molecule. Molecules of the same conformation form infinite chains joined by hydrogen bonding between a H atom on the hydroxyl group of one molecule and an N atom in the triazole ring of another molecule generated by the 2(1) screw axis. Relevant intermolecular N...O distances are 3.013 (3) and 2.806 (3) A.
Subject(s)
Xylose/analogs & derivatives , Crystallization , Hydrogen Bonding , Xylose/chemistryABSTRACT
[ReCl2(C26H22P2)2].C6H14 (I), M(r) = 1136.11, monoclinic, P2(1)/c, a = 11.426 (2), b = 13.078 (2), c = 17.323 (3) A, beta = 95.27 (1) degrees, V = 2577.7 (6) A3, Z = 2, Dx = 1.46 g cm-3, lambda(Mo K alpha) = 0.71073 A, mu = 26.5 cm-1, F(000) = 1150, T = 296 K, R = 0.034 for 3269 [Fo2 > 3 sigma(Fo2)] reflections. The Re atom in (I) is located on an inversion point, fixed at the origin. One Cl and a complete tertiary phosphine ligand (Ph2PCHCHPPh2) are situated around the Re atom so as to generate a pseudo-octahedral geometry with a P1--Re--P2 angle of 79.07 (5) degrees and P1--Re--P2' angle of 100.93 (5) degrees. The Re--Cl, Re--P1 and Re--P2 distances are 2.432 (2), 2.401 (2) and 2.398 (2) A, respectively. Bond distances and angles for the phenyl rings range from 1.34 (1) to 1.41 (1) A and 117.4 (6) to 122.0 (7) degrees with averages of 1.38 (1) A and 120.0 (1) degrees, respectively.
