Photolysis of PCl3/POCl3 with Oxygen Dopant Using 193nm ArF Excimer at Low Temperatures: Oxygen Insertion through’Phosphadioxirane’Pathway

摘要

Photolysis was performed on PCI3 and POCI3 in the presence of oxygen dopant in Armatrix at low temperatures using 193nm ArF excimer laser.The photo irradiation initially facilitated the formation of ozone in situ in the low temperature matrix.For PCI3+O2 photolysis with 193nm ArF excimer,initially POCI3 was produced and subsequent oxygen atom insertion on POCI3 generated POXCI3.Furthermore,secondary reaction channel opens up in PCI3+O2 photolysis to form a variety of photoproducts such as POCI,P~(III)O2CI,P~VO2CI and PO3CI.The insertion of oxygen atom on POCI through phosphadioxirane intermediate generated P~(III)O2CI and the direct oxygen atom addition resulted in P~VO2CI.A successive oxygen insertion on P~VO2CI triggered the PO3CI generation.The identification of all the photoproducts was confirmed through ~(18)O2 isotopic experiments and quantum chemical computations performed using density functional theory(DFT).Computations carried out at B3LYP level of theory with 6-311++G(d,p)basis set were used to correlate the structure of photo products obtained experimentally.Interestingly,photo irradiation of POCI3 with oxygen dopant in Ar matrix @193nm ArF excimer resulted in the generation of PO2CI3 PO3CI3 and PO4CI3 photo products by a sequential insertion of oxygen atoms through phosphadioxirane intermediate.A compelling evidence for the passage of the reaction through phosphadioxirane intermediate is established through ~(18)O2 isotopic substitution experiments.