Pyrazolylamidino‐ and Bis(pyrazole)manganese(I) Complexes

The pyrazolylamidino complexes fac ‐[MnBr(CO) 3 {NH=C(R)pz‐κ 2 N , N }] or fac ‐[MnBr(CO) 3 {NH=C(R)dmpz‐κ 2 N , N }] (R = CH 3 , C 6 H 5 ) are obtained by reaction of fac ‐[MnBr(CO) 3 (NCR) 2 ] and equimolar amounts of pzH or dmpzH (dmpz = 3,5‐Me 2 pz), although these reactions also afford the bis(pyrazole) complexes as by‐products. The bispyrazole complexes fac ‐[MnBr(CO) 3 (pzH) 2 ] or fac ‐[MnBr(CO) 3 (dmpzH) 2 ] are selectively obtained from [MnBr(CO) 5 ] and two equivalents of pzH or dmpzH. Their solid‐state structures, determined by X‐ray diffraction methods, show the N‐bound hydrogens of the pyrazoles pointing towards the bromine atom. The pyrazolylamidino complexes can also be prepared by reactions of equimolar amounts of the bispyrazole and the bisnitrile complexes. The solid‐state structures of the pyrazolylamidino complexes containing the dmpz fragment were determined by X‐ray diffraction methods. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)