104453-06-7Relevant academic research and scientific papers
Triphos iridium(III) halide complex photochemistry: Triphos arm dissociation
Ross, Andreas,Sharp, Paul R.
, p. 12645 - 12654 (2013/11/19)
Photolysis of Ir(triphos)X3 (triphos = 1,1,1- tris(diphenylphosphinomethyl)ethane; X = Cl, Br) yields an insoluble product believed to be oligomeric [Ir(triphos)X3]n with bridging triphos and halide ligands. Refluxing pyridine (py) dissolves the insoluble photoproducts ultimately yielding the dangling triphos complexes mer-Ir(κ2-triphos)(py)X3. Oxidation of the P center of the dangling arm of Ir(κ2-triphos)(py)Cl3 yields mer-Ir(κ2-P,P-triphosO)(py)Cl3 (triphosO = MeC(CH2P(O)Ph2)(CH2PPh2) 2), which was characterized by single-crystal X-ray diffraction. mer-Ir(κ2-triphos)(py)Cl3 is also formed when Ir(triphos)Cl3 is photolyzed in the presence of py (φ = 26%). Both mer-Ir(κ2-triphos)(py)Cl3 and mer-Ir(κ2-P,P-triphosO)(py)Cl3 photoisomerize in pyridine to their thermally unstable fac-isomers. Density functional theory (DFT) and time-dependent DFT (TDDFT) calculations suggest triphos ligand arm dissociation occurs along a triplet pathway from an initial Franck-Condon ligand-field excited state that relaxes to a Jahn-Teller axially distorted octahedral triplet with a long Ir-P bond. Subsequent triphos arm dissociation yields a distorted trigonal-bipyramidal triplet that undergoes intersystem crossing to a square pyramidal singlet.
HDS model systems. Coordination, opening, and hydrogenation of benzo[b]thiophene at iridium
Bianchini, Claudio,Meli, Andrea,Peruzzini, Maurizio,Vizza, Francesco,Moneti, Simonetta,Herrera, Verónica,Sánchez-Delgado, Roberto A.
, p. 4370 - 4381 (2007/10/02)
The η4-benzene complexes [(triphos)Ir(C6H6)]Y (Y = BPh4, 1a; PF6, 1b) react with benzo[b]thiophene (BT) at room temperature to give the unprecedented [(triphos)Ir(η3-C,C,S-C8H6S)]Y (Y = BPh4, 2a; PF6, 2b) in which intact BT is coordinated to the metal center through the S atom and the C2=C3 bond. 2a and 2b are transformed upon mild thermolysis into the iridabenzothiabenzene complexes [(triphos)Ir(η2-C,S-C8H6S)]Y (Y = BPh4, 3a; PF6, 3b). An X-ray analysis has been carried out on 3a·1.5THF·0.5EtOH. The coordination geometry around iridium may be described as a distorted trigonal-bipyramid, the metal center being surrounded by the three phosphorus atoms of triphos and by a carbon and a sulfur atom from a C-S-cleaved BT molecule. Crystal data: triclinic, space group P1, a = 17.391(3) A?, b = 16.957(4) A?, c = 12.795(3) A?, α = 77.51(2)°, β= 80.98(2)°, γ = 75.50(2)°, Z = 2, dcalcd = 1.31 g cm-3, nobsd = 7636, R = 0.072. Interaction of 2a with CO (1 atm, 20°C) yields [(triphos)Ir(CO)2]BPh4 (4) plus free BT, whereas 3a requires more drastic conditions (5 atm, 70°C) to eliminate BT and produce 4. 2a also reacts with H2 (1 atm, 20°C) to produce [(triphos)Ir(H)2(η1-S-BT)]BPh4 (5), which can be independently prepared by treatment of [(triphos)Ir(H)2(THF)]BPh4 with BT; at 5 atm H2, free BT is obtained together with [(triphos)Ir(H)3], BPh3, and benzene, as a result of a heterolytic splitting of H2 at the [(triphos)Ir(H)2]+ fragment assisted by the BPh4- counteranion. The C-S-cleaved BT in 3a is readily hydrogenated (5 atm, 20°C) to 2-ethylbenzenethiolate, producing [(triphos)Ir(H)2{o-S-(C6H4)C2H 5}] (8) plus BPh3 and benzene also via heterolytic splitting of H2 assisted by BPh4-; protonolysis of 8 with 2 equiv HCl produces (triphos)IrCl3 with concomitant liberation of 2-ethylbenzenethiol, a primary product of BT HDS. If the PF6- analogue 3b is used instead, the reaction with H2 under identical conditions yields the thiolate-bridged dimer [(triphos)IrH{μ-o-S(C6H4)C2H 5}2HIr(triphos)] (PF6)2 (9b). 3a also reacts with LiHBEt3 to give [(triphos)Ir(H)(η2-C,S-C8H6S)] (11), which converts in THF solution at 66°C into [(triphos)Ir(η3-S(C6H4)-CH=CH2)] (12) by hydride migration to C2; neither 11 nor 12 react with H2 under mild conditions. Addition of HBF4·OEt2 to 12 yields [(triphos)Ir(η4-S(C6H4)C(H)Me)]BF 4 (13c), which does react with H2 even at 1 atm to give the thiolate-bridged dimer [(triphos)IrH{μ-o-S(C6H4)C2H 5}2HIr(triphos)](BF4)2 (9c). 13c also reacts with H- to give [(triphos)IrH(η2-S(C6H4)C(H)Me)] (14), which in turn reacts with H2 and HBF4·OEt2 to yield 8 and 9c, respectively.
SOME IRIDIUM(I) AND IRIDIUM(III) COMPLEXES WITH THE TRIPOD-LIKE LIGAND CH3C(CH2PPh2)3 (triphos) AND THE X-RAY CRYSTAL STRUCTURE OF
Janser, P.,Venanzi, L. M.,Bachechi, F.
, p. 229 - 242 (2007/10/02)
The compound (1), has been reinvestigated and its X-ray crystal structure is reported.The crystals are orthorhombic, space group Pbca, with a 18.941(6), b 22.193(8), c 17.501(7) Angstroem, Z = 8.The structure was solved by the heavy atom method and refined by full-matrix least-squares to the conventional R factor value of 0.074 for 6462 reflections.The metal atom coordination is trigonal bipyramidal, with the three phosphorus atoms occupying one axial and two equatorial positions.The other equatorial position is occupied by CO while Cl is coordinated axially.Compound 1 readily undergoes a series of oxidative-addition reactions with H2, HCl and Cl2, giving + (4) + (3), and (IrCl3(triphos)> (5), respectively.Compounds (IrH(CO)(triphos)> (2) and nCl3-n(triphos)> (n = 1,2,3) have also been obtained from 1 and 5, respectively, by treating them with a variety of hydride sources.
