Discrete Hexa- and Binuclear Heterometallic Iodobismuthate(III) Complexes with Cu(I) and Ag(I)

Abstract

The rare examples of discrete anionic halobismuthates(III) with group 11 elements were obtained. Those are (3-MePyH) 6 [Bi 4 Cu 2 I 20 ] (1) and (3,5-MePyC 6 ) 3 [BiAgI 7 ] 2 (2) (3-MePyH = 3-methylpyridinium cation, 3,5-MePyC 6 =1,6bis(3,5-dimethylpyridinium)hexane dication). Both complexes were isolated as pure phases; the optical band gaps for 1 and 2 are 1.75 and 2.23 eV, respectively. 1 features one of the lowest optical band gap values among Bi/ Cu clusters. ■ EXPERIMENTAL SECTION Starting Materials. All starting components (Bi 2 O 3 , CuI, Ag 2 O, and 2,6-diMePy) were purchased from commercial sources and used without purification. 1,6-Bis(3,5-dimethylpyridinium)hexane dibromide ({(3,5-diMePy)(CH 2 ) 6 (3,5-diMePy)}Br 2 ) was synthesized via reaction between 3,5-dimethylpyridine and corresponding 1,6dibromohexane in acetonitrile. All syntheses were conducted in air.In all experiments, concentrated HI was used.Synthesis of 1 and 2. For 1, 46.6 mg (0.1 mmol) of Bi 2 O 3 and 39 μL (0.3 mmol) of 3-methylpyridinium were mixed in 1 mL of concentrated HI. The resulting solution was evaporated to dryness. Nineteen mg of CuI (0.1 mmol) was added to the residue and was dissolved in 3 mL of acetonitrile/acetone mixture (1:1) upon heating at 70 °C for 1 h. After complete dissolution of reactants, the solution was slowly cooled to room temperature. In 24 h, dark-red crystals formed. Yield: 72%.For 2, 23.3 mg (0.05 mmol) of Bi 2 O 3 , 11.6 mg of Ag 2 O (0.05 mmol), and 45 mg (0.1 mmol) of (3,5-MePy) 2 (CH 2 ) 6 Br 2 were dissolved in 7 mL of concentrated HI and acetonitrile mixture (3:4) upon heating 70 °C for 1 h. After complete dissolution of reactants, the solution was slowly cooled to room temperature. In 24 h, orange crystals formed. Yield: 76%.X-ray Diffractometry. The diffraction data for 1 and 2 were collected on a Bruker D8 Venture diffractometer (0.5°ω-and φscans, fixed-χ three circle goniometer, CMOS PHOTON III detector, Mo−I□S 3.0 microfocus source, focusing Montel mirrors, λ =