Detail of "294-93-9"

1,4,7,10-Tetraoxacyclododecane uranyl nitrate dihydrate: 1,4,7,10-Tetraoxacyclododecane uranyl nitrate dihydrate. Armagan, N. (Fen Fak., Ankara Univ., Ankara, Turk.). Acta Crystallogr., Sect. B, B33(7), 2281-4 (English) 1977. CODEN: ACBCAR. DOCUMENT TYPE: Journal CA Section: 75 (Crystallization and Crystal Structure) The structure of the title compd. was detd. by x-ray diffraction, solved by the heavy-atom method, and refined by least-squares calcns. to an R of 0.128. The crystals are monoclinic, space group P21/c, with a 9.048(5), b 14.366(8), c 6.720(26) .ANG., and .beta. 99.38(15).degree.; d.(exptl.) = 2.327 and d.(calcd.) = 2.236 for Z = 2. The mol. has a crystallocenter of symmetry which is occupied by the U atom. The uranyl group is surrounded equatorially by a near-planar hexagon comprised of 4 O atoms from the ether ring and 2 water O atoms. Intermol. binding is a result of the H bonds between nitrate O atoms and the water mols.

Crown ether complexation of titanium: synthesis and structural characterization of a cationic oxygen-bridged titanium(IV) dimer: Crown ether complexation of titanium: synthesis and structural characterization of a cationic oxygen-bridged titanium(IV) dimer. Willey, Gerald R.; Palin, Janet; Alcock, Nathaniel W. (Dep. Chem., Univ. Warwick, Coventry CV4 7AL, UK). J. Chem. Soc., Dalton Trans., (7), 1117-20 (English) 1992. CODEN: JCDTBI. ISSN: 0300-9246. DOCUMENT TYPE: Journal CA Section: 78 (Inorganic Chemicals and Reactions) Section cross-reference(s): 75 1,4,7,10-Tetraoxacyclododecane (12-crown-4) reacts with [TiCl3(MeCN)3][SbCl6] in MeCN to form a complex which provides the crown ether titanoxane [{TiCl(m-O)(12-crown-4)}2][SbCl6]2.2CH2Cl2 (1) following inadvertent hydrolysis. The structure of 1 contains a discrete {Ti2(m-O)2}+ placed on a crystallog. center of inversion, 2 regular (Oh) SbCl6- anions, and 2 mols. of CH2Cl2 as lattice solvate. 1 Crystallizes as monoclinic, space group P21/n, a 8.337(4), b 21.307(10), c 13.626(8) ?, b 107.13(4)°, Z = 2, R = 0.038, R' = 0.061. The core Ti2O2 ring is planar with dimensions Ti-O 1.823(4) and 1.811(3) ? and O-Ti-O 79.7(2) and Ti-O-Ti 100.3(2)°. In addn. to the 2 bridging O atoms each Ti atom is bonded to 1 Cl [Ti-Cl 2.277(2) ?] and all 4 O atoms of a crown macrocycle [Ti-O 2.121(4)-2.237(4), mean 2.242 ?].