Ferricenium tetrachlorobismuthate, (C 5 H 5) 2 FeBiC1 4 , crystallizes in the monoclinic space group P2 1 /c with a = 10.998(5)A, b = 17.449(4)~, c = 7.569(4)A, B = 98.46(5)~. There are four molecules in the unit cell. Reflection intensities were measured by the 8-28 scan method with a Picker FACS-1 automated diffractometer, MoKa radiation, and a graphite. 2 (2) monochromator. For 1374 data with F >3o F ; R 1 = 0.030, and R 2 = 0.037. The Bi atom is coordinated by 6 chloride ions in an irregular octahedral array; two pairs of Cl ions form halogen bridges with neighboring Bi ions resulting in an infinite chain of edge sharing octahedra. There are 6 independent Bi-Cl bond distances: 2.50(1)~ and 2.52(1)~, to nonbridging chlorines, and 2.70(1)~, 2.75(l)A, 2.95(l)A and 3.10(l)A to bridging chlorines. The bridging Cl-Bi-Cl bond angles are 80.3° and 83.9°; the ten non-bridging Cl-Bi-Cl bond angles range from 85.9° to 99.3°. The axial Cl-Bi-Cl bond angles are 166.0°, 174.5°, and 175.9°.-ii-The ferricenium cations stack between the polymer chains with cyclopentadiene rings in the eclipsed conformation, unlike the pure ferrocene molecule which shows staggered rings. The average CC distance in the rings is 1.40(2)~, the distance between ring centers is 3.40(2)~ and the Fe-ring center distance is 1.70(2)~. • '}• 60~~767-1-' C1 (2')-Bi-C1 (3) •. 87.9 (1) C1 (2')-Bi-C1 (4) 166.0(1) C 1 (3)-B i-Cl(4)

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The compound Li(NH3)4°h as been prepared by cooling solutions of lithium in liquid ammonia. X-Ray powder studies at 77°K indicate that Li(NH3)4 exists m two phases: a cubic form with a0 = 9.55 Á, stable between 82 and 89°K, and a hexagonal form having a = 7.0 A and c = 11.1 Á, stable below 82°K. At 77°K the measured density is 0.57 g/cc, corresponding to two molecules of Li(NH3)4 per hexagonal unit cell. Reflections of the type 00/ (/ odd) were not observed, suggesting that the space group is P63 or P63mc with four ammonia molecules tetrahedrally disposed about each lithium atom. The c/a ratio together with reasonable assumptions for bond lengths suggests the Li(NH3)4 tetrahedra are in hexagonal close packing. Arguments are given for believing that the molecule Li(NH3)4 is unstable to dissociation in the gas phase but that the solid compound is stable because of a large electron delocalization energy. The energy change for the reaction Li(s) + 4NH3(s) -Li(NH3)4(s) is estimated to be -20 kcal/mole.

The coordination around Ni is in the shape of a distorted octahedron, and the two five-membered rings which result from the coordination of each ida molecule are not planar or equivalent by symmetry; this distortion is related to the bond strain and H atom repulsion within each ida molecule. The two salts are not isostructural.

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