Basische Metalle, XLVI. Synthese neuartiger Carbenoid‐ und Ylidrhodium (III)‐Komplexe aus C ₅ H ₅ RhCH ₂ NC ₅ H ₅ (PMe ₃ )I]PFF ₆

Abstract

C5H5Rh(C2H4)PMe3 (1) reagiert mit CH2I2, CH2Br2, CH2ICI und CH2ICN zu den Carbenoidrhodium(III)‐Verbindungen [C5H5RhCH2X(PMe3)X′] (2–5). Aus 1 und CHX3 (X = Br, I) entstehen die Komplexe [C5H5RhCHX2(PMe3)X] (6, 7). Durch Reaktion von [C5H5RhCH2I‐(PMe3)I] (2) mit NaOCH3, NaSR (R = CH3, C6H5), KSCN und Na[AlH2(OC2H4OMe)2] (Redal) werden die Verbindungen [C5H5RhCH2OCH3(PMe3)I] (9), [C5H5RhCH2SR(PMe3)SR] (11, 12), [C5H5RhCH2SCN(PMe3)I] (13) und [C5H5RhCH3(PMe3)I] (14) erhalten. Bei der Einwirkung von NaOH auf 2 in C6H6/H2O in Gegenwart eines Phasen‐Transfer‐Katalysators tritt eine Isomerisierung zu [C5H5Rh(CH2PMe3)I2] (10) ein. Die Substitution des C‐gebundenen Iodids in 2 durch PPh3, PiPr3, NEt3, Pyridin, AsPh3, SMe2 und Tetrahydrothiophen ergibt die Komplexe [C5H5RhCH2L(PMe3)I]X (15–21), in denen die Ylide CH2PPh3, CH2PiPr3, CH2NEt3, CH2NC5H5, CH2AsPh3, CH2SMe2 und CH2SC4H8 als Liganden vorliegen. Die Kristallstruktur von 18 (L = NC5H5) wurde bestimmt. Das Ergebnis zeigt, daß das Rhodium oktaedrisch koordiniert ist und die RhC‐ und CN‐Abstände in der RhCH2NC5H5‐Gruppierung Einfachbindungslängen entsprechen. Die RhC(C5H5)‐Abstände liegen zwischen 217 (2) und 224 (3) pm und spiegeln den unterschiedlichen trans‐Einfluß der Liganden I, PMe3 und CH2NC5H5 wider.

A Novel Route to Formaldehyde and Thioformaldehyde Rhodium Complexes

“…116°C (dec. [4] 5, [22] 6, [32] C [4] [7] 36, [32] and 41, 42 [4] were prepared as described in the 22 3 }I 2 ] (9): A solution of 219.5 mg (0.69 mg (0.25 mmol) of 1 in 5 ml of ethanol was treated with 20.9 mg (0.26 mmol) of CH 3 CO 2 Na and stirred for 15 h at room temp. The mmol) of 6 in 3 ml of benzene was treated dropwise with 85 µl (1.17 mmol) of CH 2 ClI and stirred for 28 h at room temp.…”

“…It should be emphasized that even treatment of plexes containing the C 5 Me 5 Rh(PMe 3 ) unit. [16] However, as the highly reactive bis(trimethylphosphane) compounds has previously been observed for those half-sandwich type [(η 5 -C 5 H 5 )Rh(PMe 3 ) 2 ] and [(η 5 -C 5 Me 5 )Rh(PMe 3 ) 2 ] [11] with compounds with π-donating ligand, [7] [17] the metalϪcarbon formaldehyde does not lead to 26 and 27 but instead gives bond lengths [RhϪC5 and RhϪC6] trans to this ligand are the carbonyl derivatives [(η 5 -C 5 H 5 )Rh(CO) (PMe 3 )] and shorter than the other RhϪC(ring) distances.…”

“…[10] [27] Treatment of 26 and 27 with CH 2 I 2 hand, only in the latter the ion CH 2 O ϩ is observed with leads to the fast displacement of CH 2 O (detected by 1 H relatively high intensity. A plausible explanation of these NMR) and to the formation of [(η 5 -C 5 Me 5 )Rh(CH 2 I)(Presults is that due to the less pronounced donor character Me 3 )I] [4] and [(η 5 -C 5 H 5 )Rh(CH 2 I)(PMe 3 )I], [7] respectively. of C 5 H 5 compared to C 5 Me 5 and of P(OMe) 3 …”

A Novel Route to Formaldehyde and Thioformaldehyde Rhodium Complexes

“…The corresponding CϭO bond length in the vanadium complex [(η 5 -C 5 H 5 ) 2 V{κ 2 -C,O-CH 2 OC(Me)O}] ϩ is 1.236(4) Å [12] and thus almost identical to that in 22. [16] However, as the highly reactive bis(trimethylphosphane) compounds has previously been observed for those half-sandwich type [(η 5 -C 5 H 5 )Rh(PMe 3 ) 2 ] and [(η 5 -C 5 Me 5 )Rh(PMe 3 ) 2 ] [11] with compounds with π-donating ligand, [7] [17] the metalϪcarbon formaldehyde does not lead to 26 and 27 but instead gives bond lengths [RhϪC5 and RhϪC6] trans to this ligand are the carbonyl derivatives [(η 5 -C 5 H 5 )Rh(CO) (PMe 3 )] and shorter than the other RhϪC(ring) distances. [13] The RhϪC4 bond length [2.067(6) Å ] is somewhat shorter than in related cationic cyclopentadienylrhodium compounds such as [(η 5 -C 5 H 5 )Rh(CH 2 NC 5 H 5 )(PMe 3 )I] ϩ [14] and [(η 5 -C 5 H 5 )-RhCH 3 (CO)(PPh 2 R)] ϩ [R ϭ NHCH(Me)Ph] [15] which could be due to the electronic effect caused by the OAc ring.…”

“…It should be noted, however, that only CF 3 SO 3 H in a less straightforward manner and afford a in the mass spectra of 24, 26, and 27 the peak of the molemixture of products. A plausible explanation of these NMR) and to the formation of [(η 5 -C 5 Me 5 )Rh(CH 2 I)(Presults is that due to the less pronounced donor character Me 3 )I] [4] and [(η 5 -C 5 H 5 )Rh(CH 2 I)(PMe 3 )I], [7] respectively. On the other spectroscopy.…”