- Reactions and structures in the gallium(III)/indium(III)-N,N- dimethylthioformamide systems
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The structure of the N,N-dimethylthioformamide (DMTF) solvated gallium(III) ion has been determined in solution by means of extended X-ray absorption fine structure (EXAFS) spectroscopy. The gallium(III) ion is four-coordinate in tetrahedral fashion with a mean Ga-S bond distance of 2.233(2) in DMTF solution. At the dissolution of indium(III) perchlorate or trifluoromethanesulfonate in DMTF coordinated solvent molecules are partly reduced to sulfide ions, and a tetrameric complex with the composition [In4S4(SHN(CH 3)2)12]4+ is formed. The structure of the solid tetrameric complex in the perchlorate salt was solved with single crystal X-ray diffraction. Four indium(III) ions and four sulfide ions form a highly symmetric heterocubane structure where each indium binds three bridging sulfide ions and each sulfide ion binds three indium(III) ions with a mean In-S bond distance of 2.584(1) , and S-In-S angles of 90.3(1)°. Each indium(III) additionally binds three DMTF molecules at significantly longer mean In-S bond distance, 2.703(1) ; the S-In-S angles are in the range 80.3-90.4°. Large angle X-ray scattering data on a DMTF solution of indium(III) trifluoromethanesulfonate show that the same tetrameric species characterized in the solid state is also present in solution, whereas the EXAFS measurements only give information about the In-S bond distances due to the short core hole lifetime.
- Topel, ?nder,Persson, Ingmar,Lundberg, Daniel,Ullstr?m, Ann-Sofi
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- On the structure of the N,N′-dimethylpropyleneurea and dimethylsulfoxide solvated gallium(III) and indium(III) ions and bromide complexes in solution and solid state, and the complex formation of the gallium(III) and indium(III) bromide systems in N,N′-dimethylpropyleneurea
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The structures of the N,N′-dimethylpropyleneurea (DMPU) solvated gallium(III) and indium(III) ions have been determined in DMPU solution by means of EXAFS. The gallium(III) ion is five-coordinate with a mean Ga-O bond distance of 1.924(5) ?, while the larger indium(III) ion is octahedrally coordinated with a mean In-O bond distance of 2.146(3) ?. The complex formation equilibria in DMPU for the gallium(III) and indium(III) bromide systems have been studied calorimetrically at 298 K. Three relatively strong complexes are formed in the indium(III) bromide system in DMPU, whereas no stability constants could be established in the gallium(III) bromide system as the heats of complex formation were very close to zero. Gallium(III) bromide is present as DMPU solvated GaBr3 complexes in solution with three equatorial Ga-Br bonds at 2.328(3) ?, and two Ga-O bonds at 1.92(3) ? in the apical positions of a distorted trigonal bipyramid. The DMPU solvated indium(III) bromide has the same configuration with a mean In-Br bond distance of 2.510(3) ?, and two In-O bonds at 2.201(6) ?. Indium(III) binds three bromides and three Me2SO molecules through the oxygen atoms in octahedral fac-configuration with mean In-Br and In-O bond distances of 2.630(3) and 2.211(15) ?, respectively.
- Topel, ?nder,Persson, Ingmar,Lundberg, Daniel,Ullstr?m, Ann-Sofi
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- Dimethyl sulfoxide solvates of the aluminium(III), gallium(III) and indium(III) ions. A crystallographic, EXAFS and vibrational spectroscopic study
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The isostructural hexakis(dimethyl sulfoxide)-aluminium(III), -gallium(III) and -indium(III) iodides crystallise in the trigonal space group R3 (no. 148), Z = 3, at 295 ± 1 K. The metal ions are located in a 3 symmetry site with M-O bond distances of 1.894(4), 1.974(4) and 2.145(3) A, and M-O-S bond angles of 127.1(3), 124.1(3) and 123.1(2)°, for M = Al, Ga and In, respectively. The unit cell parameters are a = 10.762(2), c = 24.599(3) A, V = 2467.2(5) A3 for [Al(OS(CH 3)2)6]I3, a = 10.927(2), c = 23.868(4) A, V = 2468.1(6) A3 for [Ga(OS(CH 3)2)6]I3, and a = 11.358(2), c = 21.512(4) A, V = 2403.5(7) A3 for [In(OS(CH 3)2)6]I3. The increasing compression of the octahedral MO6 coordination entities along one three-fold axis for M = Al, Ga and In, respectively, explains why the largest ion indium(III) has the smallest unit cell volume. EXAFS measurements on the dimethyl sulfoxide solvated gallium(III) and indium(III) ions in solution and in the solid perchlorate and trifluoromethanesulfonate salts, show similar bond distances as in the solid iodide solvates. Raman and infrared spectra have been recorded for the hexakis(dimethyl sulfoxide)metal(III) iodides and the nature of the metal-sulfoxide bond has been evaluated by normal coordinate methods. The symmetric and asymmetric M-O stretching modes correspond to the vibrational frequencies 465 and 540 cm-1 for [Al(OS(CH3) 2)6]I3, 491 and 495 cm-1 for [Ga(OS(CH3)2)6]I3, and 444 and 440 cm-1 for [In(OS(CH3)2)6]I 3, respectively. The Royal Society of Chemistry 2003.
- Molla-Abbassi, Alireza,Skripkin, Mikhail,Kritikos, Mikael,Persson, Ingmar,Mink, Janos,Sandstroem, Magnus
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p. 1746 - 1753
(2007/10/03)
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- BORON, ALUMINUM, AND GALLIUM TRIS(TRIFLUOROMETHANESULFONATE) (TRIFLATE): EFFECTIVE NEW FRIEDEL-CRAFTS CATALYSTS.
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Boron, aluminum, and gallium tris(trifluoromethanesulfonate) (triflate) were prepared from the corresponding chlorides (bromides) and triflic acid. The group IIIA triflates were isolated in pure form and fully characterized (elemental analysis, molecular weight, and NMR and IR spectroscopy). Boron tris(triflate) is a monomeric, relatively volatile compound left bracket mp 43-45 degree C, bp 68-73 degree C (0. 5 Torr) right bracket , whereas aluminum and gallium triflate are associated, high-melting associated solids. Boron, aluminum, and gallium tris(triflate) are efficient new Friedel-Crafts catalysts as shown in alkylation, isomerization, and acylation reactions. Alkylation of benzene and toluene with methyl, ethyl, isopropyl, and tert-butyl halides (fluoride, chloride, and bromide) were carried out with boron, aluminum, and gallium tris(triflate) as catalyst in CH//2Cl//2 and CH//3NO//2 solvent at room temperature.
- Olah,Farooq,Morteza,Farnia,Olah
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p. 2560 - 2565
(2007/10/02)
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