Machine learning dihydrogen activation in the chemical space surrounding Vaska's complex

A machine learning exploration of the chemical space surrounding Vaska's complex.

Machine Learning Reactivity in the Chemical Space Surrounding Vaska's Complex

Machine learning models, including neural networks, Bayesian optimization, gradient boosting and Gaussian processes, were trained with DFT data for the accurate, affordable and explainable prediction of hydrogen activation barriers in the chemical space surrounding Vaska's complex.

Machine Learning Reactivity in the Chemical Space Surrounding Vaska's Complex

Machine learning models, including neural networks, Bayesian optimization, gradient boosting and Gaussian processes, were trained with DFT data for the accurate, affordable and explainable prediction of hydrogen activation barriers in the chemical space surrounding Vaska's complex.

Selective synthesis of iridium(iii) end-capped polyynes by oxidative addition of 1-iodopolyynes to Vaska's complex

The reaction of bis(triphenylphosphine)iridium(i) carbonyl chloride (Vaska's complex) with a series of 1-iodopolyynes (1-CnI and2-CnI) gave σ-polyynyl iridium(iii) complexes with general formula R(CC)nIr(PPh3)2(Cl)(I)(CO).

Systematic dismantling of a carefully designed PCcarbeneP pincer ligand via C–C bond activations at an iridium centre

An electron-rich PCsp2P ligand, incorporating N,N-dimethylamino groups para to the anchoring carbene donor of the ligand, was prepared and coordinated to iridium, producing the iridium carbene chloride 2. This species undergoes facile reaction with N2O to afford an iridaepoxide complex, 3, in which an oxygen atom has been transferred to the Ir=C bond. The rate of this reaction is significantly faster than that observed for the less electron rich, unsubstituted ligand. However, further reaction of 3 involving cleavage of one of the ligand C–C bonds was observed, producing the bis-phosphine chorido complex 4. This process was accelerated by the presence of H2. Heating 4 under H2 resulted in hydrogenolysis of the ortho-metalated phosphine ligand to give a hydrido complex (5) and decarbonylation of the acyl phosphine ligand to give, finally, Vaska’s complex analog 6. All compounds were fully characterized, and the sequence represents the dismantling of the PCsp2P ligand framework.

Back to basics: identification of reaction intermediates in the mechanism of a classic ligand substitution reaction on Vaska's complex

The mechanism of methylation of Vaska's complextrans-[ClIr(CO)(PPh3)2] by trimethylgallium was studied and the identification of the spectroscopically detected intermediates was achieved with the aid of computational methods.