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Pentamethylcyclopentadienylrhodium complexes with the pyridazine ligand. Molecular structure of [{Rh(C 5 Me 5 )} 2 (µ-Cl) 2 (µ-pydz)][ClO 4 ] 2 ·H 2 O (pydz = pyridazine)

1986; Royal Society of Chemistry; Issue: 10 Linguagem: Inglês

10.1039/dt9860002113

2050-5671

Luis A. Oro, Daniel Carmona, Fernando J. Lahoz, M. Pilar Puebla, Montserrat Esteban, Concepción Foces‐Foces, F. H. Cano,

Synthesis and Reactivity of Heterocycles

The preparation and characterization of the new mononuclear complexes [Rh(C5Me5)Cl2(pydz)], [Rh(C5Me5)Cl(pydz)2][X], and [Rh(C5Me5)(acac)(pydz)][X](pydz = pyridazine, X = BF4 or ClO4, acac = acetylacetonate) are reported. The mononuclear complex [Rh(C5Me5)Cl2(pydz)] reacts with the solvated species [Rh(C5Me5)L3][X]2(L = acetone) to form [{Rh(C5Me5)}2(µ-Cl)2(µ-pydz)][X]2. The structure of the latter complex (X = ClO4) has been determined by X-ray diffraction methods. Crystals are monoclinic, space group P21/n with Z= 4 in a unit cell of dimensions a= 22.2761(9), b= 7.940 7(1), c= 19.359 5(8)Å, and β= 109.824(3)°. The structure was solved by Patterson analysis and refined by full-matrix least-squares methods to R= 0.047 for 3 970 observed reflections. The cation consists of two Rh(C5Me5) moieties triply bridged by two chlorine atoms and a pyridazine group. The latter co-ordinates in an exo-bidentate manner through the two nitrogen atoms. The two rhodium atoms are separated by 3.397(1)Å. Attempts to isolate homovalent double-bridged complexes of general formula [Rh2(C5Me5)2Cl2(pydz)2]2+ or mixed-valence rhodium(III)-rhodium(I) complexes of formulae [(C5Me5)ClRh(µ-Cl)(µ-pydz)Rh(tfb)]+ or [(C5Me5)ClRh(µ-pydz)2Rh(tfb)]2+(tfb = 5,6,7,8-tetrafluoro-1,4-dihydro-1,4-ethenonaphthalene) have been unsuccessful.