PREPARATION OF CHIRAL DIIMINODIPHOSPHINE AND DIAMINODIPHOSPHINE LIGANDS AND THEIR CU-I AND AG-I COMPLEXES - X-RAY CRYSTAL-STRUCTURES OF [CU(1S,2S-CYCLOHEXYL-P2N2)][PF6] AND [AG(1R,2R-CYCLOHEXYL-P2N2H4)][BF4]
Wk. Wong et al., PREPARATION OF CHIRAL DIIMINODIPHOSPHINE AND DIAMINODIPHOSPHINE LIGANDS AND THEIR CU-I AND AG-I COMPLEXES - X-RAY CRYSTAL-STRUCTURES OF [CU(1S,2S-CYCLOHEXYL-P2N2)][PF6] AND [AG(1R,2R-CYCLOHEXYL-P2N2H4)][BF4], Polyhedron, 15(24), 1996, pp. 4447-4460
The interaction of optically pure 1R,2R-diammoniumyclohexane mono-(+)-
tartrate and 1S,2S-diammoniumcyclohexane mono-(-)-tartrate with 2 equi
v. of o-(diphenylphosphino)benzaldehyde in the presence of 2 equiv. of
potassium carbonate in a refluxing ethanol/water mixture gave the opt
ically pure condensation products N,N'-bis[o-(diphenylphosphino) benzy
lidene]-1R,2R-diiminocyclohexane [1R,2R-cyclohexyl-P2N2, (R,R)-I] and
nylphosphino)benzylidene]-1S,2S-diiminocyclohexane [1S,2S-cyclohexyl-P
2N2, (S,S)-I], respectively, in good yield. Reduction of optically pur
e (R,R)-I and (S,S)-I with NaBH4 in ethanol gave the optically pure re
duced products N,N'-bis[o-(diphenylphosphino) benzylidene]-1R,2R-diami
nocyclohexane [1R,2R-cyclohexyl-P2N2H4, (R,R)-II] and nylphosphino)ben
zylidene]-1S,2S-diaminocyclohexane [1S,2S-cyclohexyl-P2N2H4, (S,S)-II]
, respectively, in god yield. The coordination behaviour of I and II t
oward salts of Cu-I and Ag-I have been examined. The interaction of[Cu
(CH3CN)(4)][X] (X = ClO4-, PF6-) with 1 equiv. of optically pure L(4)[
L(4) = (R,R)-I, (S,S)-I, (R,R)-II and (S,S)-II] gave the corresponding
optically pure [CuL(4)][X] complexes, III-VI [IIIa, L(4) =(R,R)-I, X
= PF6- IIIb L(4) = (R,R)-I, X = ClO4- IV, L(4) = (S,S)-I, X = PF6-; Va
, L(4) = (R,R)-II, X = PF6-, Vb, L(4) = (R,R)-II X = ClO4-, VI, L(4) =
(S,S)-II, X = PF6-], in good yield. For the Cu-I complexes, the L(4)
ligand acted as a tetradentate ligand. However a variable-temperature
P-31 [H-1] NMR study of IIIb shows that at ambient temperature one of
the imino groups of the tetradentate ligand undergoes rapid dissociati
on to form a tridentate ligand. The interaction af AgBF4 with 1 equiv
of optically pure L(4) [L(4) = (R,R)-I, (S,S)-I, (R,R)-II and (S,S)-II
] gave the corresponding optically pure [AgL(4)][BF4] complexes, VII-X
[VII, L(4) = (R,R)-I; VIII, L(4) = (S,S)-I : IX, L(4) = (R,R)-II; X,
L(4) = (S,S)-II], in good yield. For the Ag-I complexes, the L(4) liga
nd acted as a tetradentate ligand with tilt two amino groups coordinat
ed unsymmetrically to the silver. A variable temperature P-31 [H-1] NM
R study of VII suggests that al high temperature the complex exists as
a tri-coordinated complex. The structures of IV and IX were establish
ed by X-ray diffraction studies. Copyright (C) 1996 Elsevier Science L
td