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Die Reaktionen der dimeren Kupfer(II)-acetat-Addukte L2Cu2(μ-O2CMe)4 (3a–c) mit Na[M(CO)3C5H5] (M = Mo, W) fuhren zu den heterometallischen Zweikernkomplexen C5H5(CO)2M(μ-O2CMe)2Cu(L) (4a–c, 7a, b). Als weiteres Produkt wird fur M = W die einkernige Verbindung C5H5W(CO)3OC(O)Me (8) isoliert. Die Rontgenstrukturanalyse von 4b (M = Mo, L = 4-Methylpyridin) zeigt, das die beiden Metallatome durch zwei Acetatbrucken verknupft sind und eine Mo–Cu-Bindung vorliegt. Auf gleichem Wege wie 4b sind die Zweikernkomplexe C5H5(CO)2Mo-(μ-O2CCF3)2Cu(4-MeC5H4N) (5), C5Me5(CO)2Mo(μ-O2CMe)2Cu-(4-MeC5H4N) (6) und C5H5(CO)2W(μ-O2CCF3)2Cu(4-MeC5H4N) (9) erhaltlich. Verbindung 8, die nach der Kristallstrukturanalyse eine “Four-legged-piano-stool”-Struktur besitzt, bildet sich fast quantitativ durch Umsetzung von C5H5W(CO)3CH3 (11) mit CH3CO2H/HBF4 und anschliesende Deprotonierung der isolierten Zwischenstufe [C5H5W(CO)3(CH3CO2H)]BF4 (12) mit K2CO3. Aus C5H5Mo(CO)3CH3 (13) und CH3CO2H/HBF4 entsteht analog [C5H5Mo(CO)3(CH3CO2H)]BF4 (14) und daraus mit K2CO3 ein Gemisch von C5H5Mo(CO)3OC(O)Me (15) und C5H5Mo(CO)2(η2-O2CMe) (16). Das 8 und 15 Intermediate bei der Darstellung der (CuMo)- und (CuW)-Zweikernkomplexe aus 3 und Na[M(CO)3C5H5] sind, wird durch die unabhangige Synthese von 4b und 7b aus C5H5M(CO)3OC(O)Me, MeCO2Cu und 4-Methylpyridin bestatigt. In entsprechender Weise sind die Bis-μ-(benzoato)-Komplexe C5H5(CO)2M(μ-O2CPh)2Cu(4-Me-C5H4N) (20, 23) zuganglich. Die Reaktionen von 4b bzw. 7b mit PR3 (R = Ph, Me), C2Ph2 (in Gegenwart von HBF4) und Thioessigsaure ergeben die Verbindungen cis-[C5H5M(CO)2(PR3)-OC(O)Me] (25–28), [C5H5M(CO)(C2Ph2)2]BF4 (29, 30) und C5H5Mo(CO)2(η2-OSCMe) (31). Copper(II) Acetate as a Building Block of Heterometallic Dinuclear Complexes with a CuMo and CuW Bond. The x-ray Crystal Structures of C5H5(CO)2Mo(μ-O2CMe)2Cu(4-MeC5H4N) and C5H5W(CO)3OC(O)Me The reactions of the dimeric copper(II) acetate adducts L2Cu2(μ-O2CMe)4 (3a–c) with Na[M(CO)3C5H5] (M = Mo, W) lead to the formation of the heterometallic dinuclear complexes C5H5(CO)2M(μ-O2CMe)2Cu(L) (4a–c, 7a, b). For M = W, the mononuclear compound C5H5W(CO)3OC(O)Me (8) has been isolated as a minor product. The X-ray structural analysis of 4b (M = Mo, L = 4-methylpyridine) reveals that the two metal atoms are linked by a direct CuMo bond and are also bridged by two acetate units. On the same route as 4b, the dinuclear complexes C5H5(CO)2Mo(μ-O2CCF3)2Cu(4-MeC5H4N) (5), C5Me5(CO)2Mo(μ-O2CMe)2Cu(4-MeC5H4N) (6), and C5H5(CO)2W(μ-O2CCF3)2Cu(4-MeC5H4N) (9) have been obtained. Compound 8 which owing to the X-ray analysis has a four-legged-piano-stool structure is accessible almost quantitatively on reaction of C5H5W(CO)3CH3 (11) with CH3CO2H/HBF4 followed by deprotonation of the isolated intermediate [C5H5W(CO)3(CH3CO2H)]BF4 (12) with K2CO3. Starting with C5H5Mo(CO)3CH3 (13) and CH3CO2H/HBF4, the molybdenum compound [C5H5Mo(CO)3(CH3CO2H)]BF4 (14) and from this and K2CO3 a mixture of C5H5Mo(CO)3OC(O)Me (15) and C5H5Mo(CO)2(η2-O2CMe) (16) are prepared. That 8 and 15 are intermediates in the formation of the dinuclear (Cu–Mo) and (Cu–W) complexes from 3 and Na[M(CO)3C5H5] has been confirmed by independent synthesis of 4b and 7b from C5H5M(CO)3OC(O)Me, MeCO2Cu and 4-methylpyridine. Similarly, the bis-μ-(benzoato) complexes C5H5(CO)2M(μ-O2CPh)2Cu(4-MeC5H4N) (20, 23) have been obtained. The reactions of 4b and 7b with PR3 (R = Ph, Me), C2Ph2 (in presence of HBF4), and thioacetic acid produce the compounds cis-[C5H5M(CO)2(PR3)OC(O)Me] (25–28), [C5H5M(CO)(C2Ph2)2]BF4 (29, 30), and C5H5Mo(CO)2(η2-OSCMe) (31). |
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