The neutral cyclometalated iridium(III) complexes [Ir(ppy) 2 Cl (NCNR 2 )] [ppy = 2-phenylpyridinato-C 2 ,N, R = Me 3 a, Et 3 b, 1 = 2 C 5 H 10 3 c] were prepared via the reaction of the chlorobridged dimer [Ir 2 (ppy) 4 (μ-Cl) 2 ] (1) with corresponding dialkylcyanamides NCNR 2 (2 a-c) and 3 a-c were isolated in 74-85% yields. The cationic cyclometalated iridium(III) complex [Ir (ppy) 2 (NCNMe 2 ) 2 ](OTf) (4) was obtained by replacement of chloride ligands with NCNMe 2 in 1 in the presence of AgOTf. UV/Vis absorption and emission properties of 3 a À c and 4 were studied; these complexes exhibit luminescence in the solid state upon photoexcitation (340 nm, 77 K). The characteristic feature of the X-ray structures of 3 a-c is a deviation of the fragment Ir-N-C from linearity by 13.8(5)-22.8(3)°. Quantum chemical DFT calculations and topological analysis of the electron density distribution within the formalism of Bader's theory (AIM method) performed for 3 a-c demonstrated that the Ir-N-C fragments in the optimized equilibrium structures of [Ir(ppy) 2 Cl(NCNR 2 )] significantly deviate from the linearity (by 19.8-30.7°) and indicated that the Ir-N contacts between the metal centers and dialkylcyanamide ligands are relatively weak (24-30 kcal/mol) and have a closed-shell dative interactions character. The charge decomposition analysis (CDA) shows existence of {M} ! L donation with almost negligible contribution of the {M}!L back-donation in 3 a-c.
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