P. Piret

Structure of phuralumite

Al/sub 2/[(OH)/sub 2/(PO/sub 4/)/sub 2/(UO /sub 2/)/sub 3/]. (OH)/sub 4/.10H/sub 2/O (a mineral from Kobokobo, Kivu, Zaire) is monoclinic, with space group /b P/2 /sub 1///b a/, and lattice constants, /b a/=13.836 (6), /b b /=20.918 (6), /b c/=9.428 (3) A , beta =112.44 (3) degrees , /b Z/=4, /b V/=2522 A /sup 3/, /b D//sub m/=3.5, /b D//sub c/=3.52 Mg m/sup -3/. Structure type: phosphouranylite. The [(OH)/sub 2/(PO/sub 4/)/sub 2/(UO /sub 2/)/sub 3/]/sub n//sup 2n-/ layers are connected principally by Al/sub 4/O/sub 14/ groups, composed of two octahedra and two trigonal bipyramids sharing edges.

L-(3-bromo-4-hydroxy-5-methoxy)phenylalanine

Crystals are shown to be orthorhombic, /b P/2/sub 1/2/sub 1/2/sub 1/, /b a/=15.706(3), /b b/=11.930(3), /b c/=5.930(5) A , C/sub 10/H/sub 12 /NO/sub 4/Br, /b Z/=4, /b D//sub 0/=1.7, /b D/ /sub c/=1.734 g cm/sup -3/. The torsional angle chi /sub 1 /(NC/sub alpha /C/sub beta /C/sub gamma /) is 55.7 degrees corresponding to the /b syn/ conformation.