www.elsevier.nl/locate/ica Inorganica Chimica Acta 295 (1999) 248 – 251 Note The nitrido complex (NEt 4 )[MoCl 3 (N)(OH)(MeCN)] Christoph Janiak *, Savas ¸ Temizdemir Institut fu ¨r Anorganische und Analytische Chemie, Uniersita ¨t Freiburg, Albertstr. 21, D-79104 Freiburg, Germany Received 1 June 1999; accepted 14 July 1999 Abstract The title compound tetraethylammonium-[(acetonitrile)trichlorohydroxonitridomolybdate(VI)] (1) is the product of the reaction of the nitrido complex MoCl 3 (N) with (NEt 4 )Cl·H 2 O in acetonitrile. The acetonitrile and the nitrido ligand are arranged trans, while the chloro and the hydroxo group form the equatorial plane of the pseudo-octahedral molybdenum coordination polyhedron. Complex 1 may be regarded as a presumably first step in the hydrolysis of [MoCl 4 (N)] - and supplements earlier results showing that [MoCl 4 (N)] - can be hydrolized to form [MoCl 4 (O)] - . © 1999 Elsevier Science S.A. All rights reserved. Keywords: Molybdenum complexes; Nitrido complexes; Crystal structures; Hydrolysis 1. Introduction Studies of the properties of high-valent metal – nitrido complexes are receiving constant attention [1 – 7]. The chloro(nitrido)molybdenum complexes X[Mo VI Cl 4 (N)] (X =NMe 4 , AsPh 4 [8,9], PPh 4 [10]) and (NEt 4 ) 2 - [Mo VI Cl 5 (N)] and (NEt 4 ) 2 [Mo V Cl 4 (N)] [11] are known. The crystal structures of (AsPh 4 )[Mo VI Cl 4 (N)] and (PPh 4 )[Mo VI Cl 4 (N)] have been elucidated [8,10]. In ad- dition, the structure of (PPh 3 Me) 2 [Mo V Cl 4 (N)] is avail- able, but the pyramidal [Mo V Cl 4 (N)] 2 - -anion was found disordered around a center of inversion [12]. 2. Experimental The infrared spectrum was measured on a Perkin– Elmer 783 IR spectrometer. Magnetic measurements were carried out on a Johnson Matthey magnetic sus- ceptibility balance (MSB-Auto, Gouy balance) or on a Varian O-300 NMR spectrometer according to the method of Evans [13]. Acetonitrile was dried over CaH 2 , refluxed and distilled under argon. MoCl 5 (10 g, 36.6 mmol) was stirred for four days in acetonitrile (MeCN, 60 ml). The solution slowly turned brown with the formation of a brown precipitate of MoCl 4 (MeCN) 2 [8,11]. The solvent was removed in vacuo and the remaining solid stirred for 5 h with toluene (60 ml). Then the toluene was decanted and the settled solid dried in vacuo. From this MoCl 4 (MeCN) 2 (9.03 g, 28.2 mmol) and NaN 3 (1.84 g, 28.3 mmol) were dissolved in MeCN (40 ml). Upon stirring of the mix- ture a rapid gas evolution started which ended after 1 h. A dark orange–red solution and a white precipitate (NaCl) were obtained. The solution was decanted and immediately treated with (NEt 4 )Cl···H 2 O (4.7 g, 28.3 mmol). The hygroscopic and partly wet (NEt 4 )Cl had been dried at 100°C for 2 h. Soon the solution turned red – brown and a white precipitate developed. After stirring for 35 h, the solution was filtered and concen- trated to about 20 ml. After 2 days at room tempera- ture a yellow solid had precipitated and the solution was filtered again. Cooling to -15°C yielded 5.9 g (51%) of dark-red prismatic crystals. The crystals turn opaque upon drying due to loss of the coordinated MeCN solvent molecule. IR (KBr, cm -1 ): 3350 w br, 2990 m, 2040 s (CN), 1690 m, 1460 s, 1400 m, 1310 m, 1265 w, 1185 s, 1175 sh, 1055 m, 1035 m, 1005 m, 945 s, 915 s, 790 s, 705 s, 510 w, 380 m, 330 s. Anal. of the * Corresponding author. Tel.: +49-761-203 6127; fax: +49-761- 203 6147. E-mail address: janiak@uni-freiburg.de (C. Janiak) 0020-1693/99/$ - see front matter © 1999 Elsevier Science S.A. All rights reserved. PII:S0020-1693(99)00383-7