N–PtIV–H/N–H⋯PtII intramolecular redox equilibrium in a product of H–C(sp2) cleavage and unusual alkane/arene C–H bond selectivity of ([2.1.1]pyridinophane)PtII(CH3)+Electronic supplementary information (ESI) available: experimental details. See http://www.rsc.org/suppdata/cc/b2/b207797n/
N–PtIV–H/N–H⋯PtII intramolecular redox equilibrium in a product of H–C(sp2) cleavage and unusual alkane/arene C–H bond selectivity of ([2.1.1]pyridinophane)PtII(CH3)+Electronic supplementary information (ESI) available: experimental details. See http://www.rsc.org/suppdata/cc/b2/b207797n/
[2.1.1]-(2,6)-Pyridinophane(L)-controlled alkane C–H bond cleavage: (L)PtMe2H+ as a precursor to the geometrically “tense” transient (L)PtMe+Electronic supplementary information (ESI) available: complete experimental and characterization data. See http://www.rsc.org/suppdata/nj/b3/b302055j/.
作者:Andrei N. Vedernikov、John C. Huffman、Kenneth G. Caulton
DOI:10.1039/b302055j
日期:2003.3.24
(η2-L)PtMe2 L=[2.1.1]-(2,6)-pyridinophane} is protonated at Pt to give (η3-L)PtHMe2+, where three pyridine ligands of the macrocycle L bind to Pt in a facial manner. This cation eliminates methane at a rate convenient for trapping of the T-shaped, 14-valence electron (η2-L)PtMe+ (based on DFT geometry optimization) by ethane, propane, n-butane, cyclopentane and cyclohexane to give (η3-L)Pt(olefin)H+
Hydrocarbyl Ligand “Tuning” of the Pt<sup>II/IV</sup> Redox Potential
作者:Andrei N. Vedernikov、Maren Pink、Kenneth G. Caulton
DOI:10.1021/ic034731m
日期:2004.6.1
The potentially tridentate macrocycle [2.1.1]-(2,6)-pyridinophane (L) enables the transient LPtII(CH3)(+) to cleave the C-H bond of two molecules of C6F5H. The resulting product has two aryl groups on Pt but, in contrast to nonfluorinated analogue, varies in its location of the cleaved H, as is evident from the two products (HL+)(PtR2)-R-II and (eta(3)-L)-(PtH)-H-IV(R)(2)(+). At equilibrium, the related example where R = CH3 is purely the Pt-IV redox isomer, which with R = C6H5 shows detectable populations of both isomers, and with R = C6F5 is purely the pyridine-protonated (HL+)Pt-II redox isomer. All species show a hydrogen bond from the pyridinium proton to Pt-II. Consistent with the idea that electron-withdrawing R makes platinum(II) more resistant to oxidation (i.e., a proton on Pt), and thus less Bronsted basic, the (1)J(PtH) coupling constant falls in the series R = Me (90 Hz), R = C6H5 (86 Hz), and R = C6F5 (63 Hz).