Synthesis of Half‐Sandwich Tungsten Chlorogermyl and Chlorostannyl Complexes

Abstract

The reaction of the dichlorogermane Me2GeCl2 and stannanes R2SnCl2 (R = Me, Bu) with the alkali tungsten salts M[(η5‐C5R′5)L(OC)2W] (L = CO, PPh3; M = Li, Na; R′ = H, Me) yields via alkali salt elimination a range of novel chlorostannyl‐ and chlorogermyl‐functionalized tungsten complexes of the general formula [(η5‐C5R′5)L(OC)2W(ER2Cl)] (R′ = H, Me; L = CO, PPh3; E = Ge, Sn; R = Me, Bu) (3a–e). The use of the phosphane‐substituted tungsten anion Na[(η5‐C5Me5)(Ph3P)(OC)2W] (1c) and Me2SnCl2 leads to a mixture consisting of the mono‐ (3e) as well as the di‐substituted stannyl compound [{(η5‐C5H5)(Ph3P)(OC)2W}2(SnMe2)] (4). Access to 3a is also given by reaction of ClMe2Sn–C5H5 (5) with [(MeCN)3W(CO)3] which includes chemoselective tin shift from the cyclopentadiene to the tungsten atom. In addition, a successive chlorination of [(η5‐C5H5)(OC)3W(SnMe3)] (6) via [(η5‐C5H5)(OC)3W(SnMe2Cl)] (3a) and [(η5‐C5H5)(OC)3W(SnMeCl2)] (7) to [(η5‐C5H5)(OC)3W(SnCl3)] (8) is presented. All new compounds have been fully characterized by elemental analyses and in solution by IR and multinuclear NMR spectroscopy. The crystal structures of complexes 3b–d and 8 were presented and discussed, showing bond lengths of 2.6272(4) Å for Ge–W, 2.7959(5) (3b), 2.7866(3) (3d) and 2.7244(3) (8) Å for the Sn–W bonds.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Structural characterization of the anionic halfsandwich complex and its reactivity towards stannanes and distannanes

“…Subsequently, Bichler et al were able to obtain 4 by chlorination of 2 with HCl/pentane, however, under rather harsh conditions (120°C/8 h) and without providing information as to the yield of this synthesis [28]. Based on our previous work on corresponding tungsten chlorostannyl complexes [16], we obtained 4 upon reaction of 2 with SnCl 4 as chlorinating agent according to Fig. 5.…”

“…Elemental analyses (C, H) were obtained from a Vario Micro (Elementar Analysensysteme). Li ½Moðg 5 -C 5 H 5 ÞðCOÞ 3 [16], t Bu 2 (Cl)Sn-Sn(Cl) t Bu 2 [30], ½Moðg 5 -C 5 H 5 Þ-ðSnMe 3 ÞðCOÞ 3 [25] and ½fMoðg 5 -C 5 H 5 ÞðCOÞ 3 g 2 SnMe 2 [26] were prepared according to the literature procedures. All other chemicals were obtained commercially and used without further purification.…”

“…The outstanding preparative versatility of this route has led to a vast range of organometallic species so far, most of which have been obtained from group 13 [4][5][6][7][8][9][10][11][12][13][14][15] and group 14 precursors [16][17][18][19][20].…”

Coordination Chemistry of the Tris(pentafluoroethyl)stannate(II) Anion, [Sn(C2F5)3]–

“…The C-Sn-C bond angles range from 96.2(3) to 104.4(3)°and are on average (100.8°) as expected larger than for the free [Sn(C 2 F 5 ) 3 ] -[91.3(av)°]. However, the Sn-Zn-Sn angle of 158.04(4)°clearly deviates from linearity, which is due to additional interactions 255.29 (6) [W(CO) 3 {η 5 -C 5 H 4 (SnMe 3 )}(SnMe 3 )] [12] 284.81(5) [W(CO) 3 Cp(SnClBu 2 )] [13] 279.59(5) [W(CO) 3 Cp(SnClMe 2 )] [13] 278.66(3) [W(CO) 3 Cp{Sn(C 2 F 5 ) 3 }] 273.94(6) [W(CO) 3 {η 5 -C 5 H 4 (SnClMe 2 )}(SnCl 2 Me)] [12] 272.56(3) [W(CO) 3 Cp(SnCl 3 )] [13] 272.44 (3) [Fe(CO) 2 {η 5 -C 5 H 4 (SiMe 3 )}{Sn(OH) t Bu 2 }] [14] 253.4(1) [Fe(CO) 2 {η 5 -C 5 H 4 (SiMe 3 )}(SnCl t Bu 2 )] [14] 252.9(2) [Fe(CO) 2 Cp{Sn(C 2 F 5 ) 3 }] 247.18(4) [Fe(CO) 2 Cp(SnCl 2 Ph)] [15] 246.7(2) [Fe(CO) 2 Cp(SnBr 3 )] [16] 246.2 (2) [Ni(CO) 3 between the zinc atom and three fluorine atoms of two ancillary [Zn{Sn(C 2 F 5 ) 3 } 2 ] (1) molecules which range from 265.8(6) pm to 275.8(5) pm. The Sn-C bond lengths, which range from 221.1(9) pm to 223.5(9) pm, experience a shortening with respect to the anion [Sn(C 2 F 5 ) 3 ] -[226.5(av) pm], and nicely matches with the corresponding distances in the stannane HSn(C 2 F 5 ) 3 [220.6(av) pm].…”

“…[W(CO) 3 {η 5 -C 5 H 4 (C 2 H 4 NMe 2 )}(SnCy 3 )] [21] 1987, 1911, 1891 [W(CO) 3 {η 5 -C 5 H 4 (C 2 H 4 NMe 2 )}(SnPh 3 )] [21] 1992, 1916, 1894 [W(CO) 3 Cp*(SnClMe 2 )] [13] 1997, 1927, 1901 [W(CO) 3 Cp(SnClBu 2 )] [13] 1999, 1981 [W(CO) 3 Cp(SnClMe 2 )] [13] 2010, 1940, 1911 [W(CO) 3 {η 5 -C 5 H 4 (SnMe 3 )}(SnClMe 2 )] [12] 2010, 1940, 1911 [W(CO) 3 {η 5 -C 5 H 4 (SnClMe 2 )}(SnClMe 2 )] [12] 2016, 1944, 1915 [W(CO) 3 {η 5 -C 5 H 4 (SnMe 3 )}(SnMe 3 )] [12] 2016, 1947, 1915 [W(CO) 3 Cp{Sn(C 2 F 5 ) 3 …”