title: Dirhodium formamidinate compounds with bidentate nitrogen chelating ligands.
abstract: The reactions of [Rh(2)(DTolF)(2)(CH(3)CN)(6)][BF(4)](2) (1) (DTolF = N,N'-di-p-tolylformamidinate) with 2,2'-bipyridine (bpy) and 1,10-phenanthroline (phen) proceed with substitution of CH(3)CN molecules to give products with the N-N ligands chelating in an equatorial-equatorial (eq-eq) fashion. Compound 1 reacts with 1 equiv of bpy to yield a mixture of [Rh(2)(DTolF)(2)(bpy)(CH(3)CN)(3)][BF(4)](2).(CH(3))(2)CO (2a) and [Rh(2)(DTolF)(2)(bpy)(CH(3)CN)(4)][BF(4)](2) (2b). Compound 2a crystallizes in the monoclinic space group P2(1)/n with a = 13.5856(2) A, b = 18.0402(2) A, c = 21.4791(3) A; alpha = 90 degrees, beta = 101.044(1) degrees, gamma = 90 degrees; V = 5167.27(12) A(3), Z = 4, R = 0.0531, and R(w) = 0.0948. Compound 2b crystallizes in the monoclinic space group P2(1)/n with a = 10.9339(2) A, b = 24.4858(1) A, c = 19.4874(3) A; alpha = 90 degrees, beta = 94.329(1) degrees, gamma = 90 degrees; V = 5202.38(13) A(3), Z = 4, R = 0.0459, and R(w) = 0.1140. The reaction of compound 1 with 2 equiv of bpy affords [Rh(2)(DTolF)(2)(bpy)(2)(CH(3)CN)][BF(4)](2) (3) which crystallizes in the monoclinic space group P2(1)/a with a = 19.4534(4) A, b = 13.8298(3) A, c = 19.8218(5) A; alpha = 90 degrees, beta = 109.189(1) degrees, gamma = 90 degrees; V = 5036.5(2) A(3), Z = 4, R = 0.0589, and R(w) = 0.0860. Compound 1 reacts with 1 equiv of phen to form [Rh(2)(DTolF)(2)(phen)(CH(3)CN)(3)][BF(4)](2).2C(2)H(5)OC(2)H(5) (4) which crystallizes in the triclinic space group P1macro with a = 12.6346(2) A, b = 13.5872(2) A, c = 19.0597(3) A; alpha = 71.948(1) degrees, beta = 73.631(1) degrees, gamma = 71.380(1) degrees; V = 2886.70(8) A(3), Z = 2, R = 0.0445, and R(w) = 0.1207. A notable feature of the cations in 2a, 3, and 4 is the presence of only one axial (ax) CH(3)CN ligand, a fact that can be attributed to the steric effect of the formamidinate bridging ligands. Compounds 2a, 2b, 3, and 4 were fully characterized by X-ray crystallography and (1)H NMR spectroscopy, whereas [Rh(2)(DTolF)(2)(phen)(2)(CH(3)CN)(2)][BF(4)](2) (5) was characterized by (1)H NMR spectroscopy.
authors.affiliation: Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA.
authors.forename: Helen T
authors.initials: HT
authors.lastname: Chifotides
authors.forename: Kemal V
authors.initials: KV
authors.lastname: Catalan
authors.forename: Kim R
authors.initials: KR
authors.lastname: Dunbar
mesh_terms: D015082:2,2'-Dipyridyl / Q000737:chemistry; D002614:Chelating Agents / Q000737:chemistry; D018360:Crystallography, X-Ray; D004563:Electrochemistry; D005559:Formamides / Q000138:chemical synthesis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009584:Nitrogen / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010618:Phenanthrolines / Q000737:chemistry; D012238:Rhodium / Q000737:chemistry*
chemical_list: D002614:Chelating Agents; D005559:Formamides; D009942:Organometallic Compounds; D010618:Phenanthrolines; D015082:2,2'-Dipyridyl; D012238:Rhodium; D009584:Nitrogen; C025205:1,10-phenanthroline