Search results for "Chromium complexes"
showing 3 items of 3 documents
Chiral α-P,N Ligands From a Diastereoselective Ph2PH Addition to (η6-Benzaldimine)tricarbonylchromium Complexes
1999
International audience; Chiral α-aminophosphane (α-P–C–N) ligands have been prepared by reversible addition of Ph2PH to tricarbonylchromium benzaldimine complexes (CO)3Cr[η6-o-C6H4(Y)(CH=NR)] (with Y, R = CH3, CH3 or CH2COOCH3; CH3O, CH3 or p-CH3OC6H4; Cl, C6H5), with complete diastereoselectivity. These complexes are stabilized in solution by electron-withdrawing group(s) on the imine.
A polymeric two-dimensional mixed-metal network. Crystal structure and magnetic properties of {[P(Ph)4][MnCr(ox)3]}
1994
Abstract The mixed-metal ferromagnet {[P(Ph) 4 ][MnCr(ox) 3 ]} n , where Ph is phenyl and ox is oxalate, has been prepared and a two-dimensional network structure, extended by Mn(II)-ox-Cr(III) bridges, has been determined from single crystal X-ray data. Crystal data: space group R 3 c , a = b =18.783(3), c =57.283(24) A, α=β=90, γ=120°, Z =24 (C 30 H 20 O 12 PCrMn). The magnetic susceptibility data obey the Curie-Weiss law in the temperature range 260–20 K with a positive Weiss constant of 10.5 K. The temperature dependence of the molar magnetization exhibits a magnetic phase transition at T c =5.9 K. The structure is discussed in relation to the strategy for preparing molecular based ferr…
[Cr(dpa)(ox)2]–: a new bis-oxalato building block for the design of heteropolymetallic systems. Crystal structures and magnetic properties of PPh4[Cr…
2001
[EN] The new complexes of formulae PPh4[Cr(dpa)(ox)(2)] (1), AsPh4[Cr(dpa)(OX)(2)] (2), Hdpa[Cr(dpa)(ox)(2)]-4H(2)O (3), Rad[Cr(dpa)(ox)(2)] . H2O (4) and Sr[Cr(dpa)(ox)(2)](2) . 8H(2)O (5) [PPh4 = tetraphenylphosphonium cation; AsPh4 = tetraphenylarsoniurn cation; dpa = 2,T-dipyridylamine; ox = oxalate dianion; Rad = 2-(4-N-methylpyridinium)4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-a-oxyl-3-N-oxide] have been prepared and characterised by single-crystal X-ray diffraction. The structures of 1-4 consist of discrete [Cr(dpa)(ox)(2)](-) anions, tetraphenylphosphonium. (1), tetraphenylarsonium (2), monoprotonated Hdpa (3) and univalent radical (4) cations and uncoordinated water molecules (2-…