STRUCTURES OF 3 COMPOUNDS INVOLVING LITHIUM-ION ENCAPSULATION BY GROUP-6 CARBONYL PHOSPHINITE CROWN-ETHER COMPLEXES

Lithium fac-benzoyl-cis-{1,11-bis[2-(1,3-dimethyl-1,3,2-diazaphospholidinyl)]-4,8-dimethyl-4,8-diaza-1,11-dioxaundecane-P,P'}tricarbonylmolybdenum, (I), Li[Mo(C7H5O){(C4H10N2P)2C9H20N2O2}(CO)3], M(r) = 714.5, monoclinic, P2(1)/c, a = 10.996 (2), b = 17.051 (3), c = 18.437 (4) angstrom, beta = 103.90 (1)-degrees, U = 3356 angstrom-3, Z = 4, D(x) = 1.41 g cm-3, Mo K-alpha-radiation, lambda = 0.71069-angstrom, mu-(Mo K-alpha) = 5.2 cm-1, F(000) = 1488, T = 298 K, R = 0.0345 (wR = 0.0442) for 3008 observed [I > 3-sigma-(I)] reflections. Lithium fac-benzoyl-cis-[1,7-bis(diphenylphosphinito)-4-methyl-4-azaheptane-P,P']tricarbonylmolybdenum dichloromethane solvate, (II), Li[Mo(C7H5O){(C12H10P)2C7H15NO2}(CO)3].3/2CH2Cl2, M(r) = 935.0, triclinic, P1BAR, a = 13.007 (3), b = 17.257 (3), c = 20.397 (4) angstrom, alpha = 95.13 (2), beta = 102.66 (2), gamma = 95.78 (2)-degrees, U = 4415-angstrom-3, Z = 4, D(x) = 1.41 g cm-3, Mo K-alpha-radiation, lambda = 0.71069-angstrom, mu-(Mo K-alpha) = 5.9 cm-1, F(000) = 1916, T = 298 K, R = 0.0724 (wR = 0.0787) for 7605 observed [I > 3-sigma-(I)] reflections. Lithium fac-benzoyl-tricarbonyl-cis-[3-(diphenylphosphinitomethyl)-1-(3-diphenylphosphinitopropyl)piperidine-P,P']molybdenum, (III), Li[Mo(C7H5O){(C12H10P)2C9H17NO2}(CO)3], M(r) = 833.7, monoclinic, P2(1), a = 10.811 (2), b = 16.398 (3), c = 11.432 (2) angstrom, beta = 100.99 (2)-degrees, U = 1990 angstrom-3, Z = 2, D(x) = 1.39 g cm-3, Mo K-alpha-radiation, lambda = 0.71069-angstrom, mu-(Mo K-alpha) = 4.5 cm-1, F(000) = 860, T = 298 K, R = 0.0317 (wR = 0.0374) for 3145 observed [I > 3-sigma-(I)] reflections. All three compounds contain lithium encapsulated inside different bis(phosphinito)molybda crown ligands with the remaining vertex being the O atom of the benzoylate group on molybdenum. In (I) the molecule has approximate mirror symmetry while in both independent molecules in the asymmetric unit of compound (II) the mirror symmetry is broken by slight twists of the benzoylate phenyl ring away from the mirror plane and by some disorder in the OCH2CH2O linkages. In compound (III) the unsymmetrical crown ligand forces an approximately perpendicular arrangement in the 'equatorial' and 'axial' phenyl rings on the phosphinito P atoms. In (I) the resultant geometry about Li+ is a square pyramid with Li...O distances of 1.899 (8), 2.125 (9) and 2.137 (8) angstrom and Li...N distances of 2.205 (9) and 2.227 (9) angstrom. In (II) and (III) the Li+ geometries are distorted tetrahedra with Li...O = 1.88 (2), 1.93 (2) and 1.93 (2) angstrom and Li...N = 2.03 (2) angstrom in the ordered molecule of compound (II) and with the corresponding distances in compound (III) 1.854 (11), 1.909 (10), 1.942 (11) and 2.092 (11) angstrom respectively. In each case the shortest distance involves the benzoylato O atom and is reflected in small changes in the C = O distances. The geometries of the Mo atom in each complex are distorted octahedra and the Mo-P distances and PMoP bond angles [2.474 (1) and 2.477 (1) angstrom, 99.53 (4)-degrees (I); 2.473 (3)-2.491 (3) angstrom, 96.31 and 98.71 (8)-degrees (II); and 2.492 (2) and 2.500 (2) angstrom and 96.28 (5)-degrees (III)] are reasonably consistent with the estimated steric sizes of the phosphinito ligands.