Preparation and crystal structure of uranium(IV) borohydride-n-propyl ether

Abstract

Uranium(IV) borohydride reacts with di-n-propyl ether to form U(BH/sub 4/)/sub 4/.O(n-C/sub 3/H/sub 7/)/sub 2/, a light green solid that can be sublimed at 30 to 40/sup 0/C and 10/sup -5/ mm. Structural characterization by single-crystal x-ray diffractometry has shown the molecule to contain two uranium atoms in different environments. One uranium atom is bonded to oxygen of two ether molecules and via 11 hydrogen atoms to 4 borohydride ions. The other uranium has 14 hydrogen neighbors from 5 borohydride ions, one of which acts as a bridge to the first uranium atom. This unsymmetrical dimer is in marked contrast to the linear polymeric chain structures of U(BH/sub 4/)/sub 4/.O(CH/sub 3/)/sub 2/ and U(BH/sub 4/)/sub 4/.O(C/sub 2/H/sub 5/)/sub 2/. The propyl compound is triclinic, space group P anti 1, with a = 12.043 (10) A, b = 10.340 (8) A, c = 14.752 (13) A, ..cap alpha.. = 82.81 (5)/sup 0/, ..beta.. = 112.99 (5)/sup 0/, ..gamma.. = 110.76 (5)/sup 0/, Z = 4, and d/sub calcd/ = 1.68 g cm/sup -3/ at 22/sup 0/C. R = 0.063 for 833 reflections, with I greater than 3 sigma and with restraints on the bond distances and some of the bond angles. 2more » tables, 3 figures.« less