ISSN:
0044-2313
Keywords:
Phosphanimine
;
Phosphoraneiminato Complexes of Iron
;
Syntheses
;
IR Spectra
;
Crystal Structure
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
Phosphanimine and Phosphoraneiminato Complexes of Iron. The Crystal Structures of [FeCl3(Me3SiNPEt3)], [FeCl2(Me3SiNPEt3)]2, [FeCl2(NPEt3)]2, and [Fe(O2C—CH3)2(NPEt3)]2The phosphanimine complexes [FeCl3(Me3SiNPEt3)] (red-orange) and [FeCl2(Me3SiNPEt3)]2 (colourless) have been prepared by reactions of Me3SiNPEt3 with FeCl3 and FeCl2, respectively, in CH2Cl2 suspensions. Thermal decomposition of these donor-acceptor complexes in boiling toluene leads to the phosphoraneiminato complex [FeCl2(NPEt3)]2 (black), whereas [Fe(O2C—CH3)2(NPEt3)]2 (brown) is formed from iron(II) acetate and Me3SiNPEt3 in boiling acetonitrile. The complexes are characterized by IR spectroscopy and by crystal structure determinations.[FeCl3(Me3SiNPEt3)] (1): Space group P21/c, Z = 8, structure determination with 4 673 unique reflections, R = 0.033. Lattice dimensions at -15°C: a = 1 607.8, b = 1 602.0, c = 1 417.2 pm, β = 106.56°. 1 forms monomeric molecules with tetrahedrally coordinated iron atoms. Bond lengths in average: Fe—N = 196.9 pm, Fe—Cl = 219.7 pm.[FeCl2(Me3SiNPEt3)]2 (2): Space group P21/c, Z = 4, structure determination with 4 992 unique reflections, R = 0.048. Lattice dimensions at 20°C: a = 1 457.9, b = 1 685.4, c = 1 507.3 pm, β = 116.74°. 2 forms dimeric molecules, which are associated by chloro bridges. The iron atoms are tetrahedrally coordinated with trans positions of the phosphanimine ligands. Both lengths in average: Fe—N = 202.2 pm, Fe—Clterminal = 224.7 pm, Fe—Clbridge = 241.0 pm.[FeCl2(NPEt3)]2 (3): Space group P21/n, Z = 2, structure determination with 2763 unique reflections, R = 0.039. Lattice dimensions at -70°C: a = 799.1, b = 1009.0, c = 1441.9 pm, β = 93.45°. 3 forms centrosymmetric dimeric molecules, in which the tetrahedrally coordinated iron atoms are associated by the nitrogen atoms of the phosphoraneiminato ligands. Bond lengths in average: Fe—N = 191.4 pm, Fe—Cl = 222.7 pm.[Fe(O2C—CH3)2(NPEt3]2 (4): Space group P21/n, Z = 2, structure determination with 3005 observed unique reflections, R = 0.034. Lattice dimensions at -65°C: a = 886.4, b = 1444.6 pm, β = 90.60°. 4 forms centrosymmetric dimeric molecules, in which the octahedrally coordinated iron atoms are associated by the nitrogen atoms of the phosphoraneiminato ligands with bond lengths Fe—N of 191.9 and 195.0 pm. The acetate groups are coordinated in a chelating fashion.
Notes:
Die Phosphanimin-Komplexe [FeCl3(Me3SiNPEt3)] (rotorange) und [FeCl2(Me3SiNPEt3)]2 (farblos) entstehen durch Reaktion von FeCl3 bzw. FeCl2 mit Me3SiNPEt3 in CH2Cl2-Suspensionen. Erhitzen dieser Donor-Akzeptorkomplexe in Toluol führt zu dem Phosphaniminatoderivat [FeCl2NPEt3)]2 (schwarz), während [Fe(O2C—CH3)2 · (NPEt3)]2 (braun) aus Eisen(II)-acetat und Me3SiNPEt3 in siedendem Acetonitril entsteht. Die Komplexe werden durch die IR-Spektren und durch Kristallstrukturanalysen charakterisiert.[FeCl3(Me3SiNPEt3)] (1): Raumgruppe P21/c, Z = 8, Strukturlösung mit 4 673 unabhängigen Reflexen, R = 0,033. Gitterkonstanten bei -15°C: a = 1 607,8; b = 1 602,0; c = 1 417,2 pm, β = 106,56°. 1 hat eine monomere Molekülstruktur mit tetraedrisch koordiniertem Eisenatom und mittleren Bindungslängen Fe—N = 196,9 pm, Fe—Cl = 219,7 pm.[FeCl2(Me3SiNPEt3)]2 (2): Raumgruppe P21/c, Z = 4, Strukturlösung mit 4 992 unabhängigen Reflexen, R = 0,048. Gitterkonstanten bei 20°: a = 1 457,9; b = 1 685,4; c = 1 507,3 pm, β = 116,74°. 2 bildet dimere, über Chlorobrücken assoziierte Moleküle mit tetraedrisch koordinierten Eisenatomen und trans-Stellung der Phosphanimin-Liganden. Mittlere Bindungslängen: Fe—N = 202,2 pm, Fe—Clterminal = 224,7 pm, Fe—ClBrücke = 241,0 pm.[FeCl2(NPEt3)]2 (3): Raumgruppe P21/n, Z = 2, Strukturlösung mit 2 763 unabhängigen Reflexen, R = 0,039. Gitterkonstanten bei -70°C: a = 799,1; b = 1 009,0; c = 1 441,9 pm, β = 93,45°. 3 bildet zentrosymmetrische dimere Moleküle, in denen die tetraedrisch koordinierten Eisenatome über die N-Atome der Phosphaniminatoliganden assoziiert sind. Mittlere Bindungslängen: Fe—N = 191,4 pm, Fe—Cl = 222,7 pm.[Fe(O2C—CH3)2(NPEt3)]2 (4): Raumgruppe P21/n, Z = 2, Strukturlösung mit 3 005 unabhängigen beobachteten Reflexen, R = 0,034. Gitterkonstanten bei -65°C: a = 886,4; b = 1 112,7; c = 1 444,6 pm; β = 90,60°. 4 bildet zentrosymmetrische dimere Moleküle, in denen die oktaedrisch koordinierten Eisenatome über die N-Atome der Phosphaniminatoliganden mit Fe—N-Abständen von 191,9 und 195,0 pm assoziiert sind. Die Acetatgruppen sind chelatartig gebunden.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/zaac.19956210502
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