Preparation of methylhydrazine and methyldiazene complexes of molybdenum and tungsten

Nitrosyl complexes [M(CO) 3(NO)L 2]BPh 4 (2, 5) [M = Mo, W; L = PPh(OEt) 2, PPh 2OEt] were prepared by allowing carbonyl compounds M(CO) 4L 2 (1, 4) to react with NOPF 6 in CH 2Cl 2. Dicarbonyl complex [W(CO) 2(NO){PPh(OEt) 2} 3]BPh 4 (7) was also prepared by reacting W(CO) 3[PPh(OEt) 2] 3 (6) with NOPF 6. Treatment of nitrosyl complexes 2, 5 with [NEt 4]Br gave bromide derivative [MBr(CO) 2(NO)L 2]BPh 4 (3). Hydrazine complexes [M(CO)(RNHNH 2)(NO)L 3]BPh 4 (8, 9, 10) (R = H, CH 3) were prepared by allowing nitrosyl complexes 2, 5 to react with hydrazine RNHNH 2 in CH 2Cl 2. Reaction of methylhydrazine complexes [M(CO)(CH 3NHNH 2)(NO)L 3]BPh 4 (8, 10) with Pb(OAc) 4 at -30°C resulted in selective oxidation of hydrazine, affording the corresponding methyldiazene derivatives [M(CO)(CH 3NNH)(NO)L 3]BPh 4 (11, 12). The complexes were characterised spectroscopically (IR and NMR), and a geometry in solution was also established. © 2012 Elsevier Ltd. All rights reserved.