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Reaction of poly(vinyl chloride) (PVC) with 5 equiv. of triethyl silane in THF, in the presence of in situ generated (xantphos)RhCl catalyst, results in partial reduction of PVC via hydrodechlorination to yield poly(vinyl chloride- co -ethylene). Increasing catalyst loading or using N , N -dimethylacetamide (DMA) as a solvent both diminished selectivity for hydrodechlorination, promoting competitive dehydrochlorination reactions. Reaction of PVC with 2 equiv. of sodium formate in THF in the presence of (xantphos)RhCl affords excellent selectivity for hydrodechlorination along with complete PVC dechlorination, yielding polyethylene-like polymers. Higher catalyst loadings were necessary to activate PVC towards reduction in this case. In contrast, reaction of PVC with 1 equiv. of NaH in DMA, in the presence of (xantphos)RhCl, exhibited good selectivity for dehydrochlorination, as well as much higher reaction rates. These results combined shed light on the interplay between critical reaction parameters that control PVC's mode of reactivity. 

This work implements a genetic algorithm (GA) to discover organic catalysts for photoredox CO 2 reduction that are both highly active and resistant to degradation. The lowest unoccupied molecular orbital energy of the ground state catalyst is chosen as the activity descriptor and the average Mulliken charge on all ring carbons is chosen as the descriptor for resistance to degradation via carboxylation (both obtained using density functional theory) to construct the fitness function of the GA. We combine the results of multiple GA runs, each based on different relative weighting of the two descriptors, and rigorously assess GA performance by calculating electron transfer barriers to CO 2 reduction. A large majority of GA predictions exhibit improved performance relative to experimentally studied o-, m-, and p-terphenyl catalysts. Based on stringent cutoffs imposed on the average charge, barrier to electron transfer to CO 2 , and excitation energy, we recommend 25 catalysts for further experimental investigation of viability toward photoredox CO 2 reduction. 

Three complexes based on an Ir–M (M = FeII, CoII, and NiII) heterobimetallic core and 2-(diphenylphosphino)pyridine (Ph2PPy) ligand were synthesized via the reaction of trans-[IrCl(CO)(Ph2PPy)2] and the corresponding metal chloride. Their structures were established by single-crystal X-ray diffraction as [Ir(CO)(μ-Cl)(μ-Ph2PPy)2FeCl2]·2CH2Cl2 (2), [IrCl(CO)(μ- Ph2PPy)2CoCl2]·2CH2Cl2 (3), and [Ir(CO)(μ-Cl)(μ-Ph2PPy)2NiCl2]·2CH2Cl2 (4). Time-dependent DFT computations suggest a donor-acceptor interaction between a filled 5dz2 orbital on iridium and an empty orbital on the first-row metal atom, which is supported by UV-vis studies. Magnetic moment measurements show that the first-row metals are in their high- spin electronic configurations. Cyclic voltammetry data show that all the complexes undergo irreversible decomposition upon either reduction or oxidation. Reduction of 4 proceeds through ECE mechanism. While these complexes are not stable to electrocatalysis conditions, the data presented here refine our understanding of the bonding synergies of the first-row and third-row metals.