Facile synthesis and structures of silver formamidinates and pyrazolates

Abstract

Dinuclear silver formamidinates, [Ag2(DFForm)2(py)2] (1) (DFForm, N,N′-bis(2,6-difluorophenyl)formamidinate, py = pyridine), [Ag2(mHForm)2(py)3] (2) and [Ag2(mHForm)2(CH3CN)2] (2a) (mHForm, N,N′-bis(2,3,4,6-tetrafluorophenyl)formamidinate), [Ag2(pHForm)2(py)3] (3) (pHForm, N,N′-bis(2,3,5,6-tetrafluorophenyl)formamidinate), [Ag2(PFForm)2(py)3] (4) (PFForm, N,N′-bis(2,3,4,5,6-pentafluorophenyl)formamidinate) and [Ag2(DippForm)2]·1.25CH2Cl2 (5) (DippForm, N,N′-bis(2,6-diisopropylphenyl)formamidinate), and polynuclear, mainly trinuclear, silver pyrazolates, [Ag3(Ph2pz)3]2 (6) (Ph2pz, 3,5-diphenylpyrazolate), [Ag(tBu2pz)]4 (7) (tBu2pz, 3,5-di-tert-butylpyrazolate), [Ag3(PhMepz)3] (8) (PhMepz, 3-methyl-5-phenylpyrazolate), [Ag3(Phtpz)3] (9) (Phtpz, 3-phenyl-5-(2-thienyl)pyrazolate), [Ag3(ttfpz)3] (10) (ttfpz, 3-(2-thienyl)-5-trifluoromethylpyrazolate) and [Ag2(Me2pz)(PPh3)4Cl] (11) (Me2pz, 3,5-dimethylpyrazolate) were successfully synthesized in good yield by treating silver(i) oxide with the corresponding formamidines (FormH) or pyrazoles (pzH) either in pyridine or acetonitrile. These rapid, easily handled and economical reactions are readily monitored by consumption of black silver oxide. All compounds are potential precursors in redox transmetallation reactions in the synthesis of lanthanoid and alkaline earth pyrazolate and formamidinate complexes.