Informação quântica e ressonância magnética nuclear: otimização de parâmetros espectroscópicos de heterociclos fosforados

Abstract

Quantum computing is the field of science that uses quantum-mechanical phenomena, such as superposition and entanglement, to perform operations on data. The fundamental information unit used in quantum computing is the quantum bit or qubit. It is well-known that quantum computers could theoretically be able to solve problems much more quickly than any classical computers. Currently, the first and still the most successful implementations of quantum information processing have been based on nuclear spins in liquids. However, molecules that enable many qubits NMR quantum information processing should meet some conditions: have large chemical shifts-δ and be appropriately dispersed for qubit addressability, appreciable spin-spin coupling-J between any pair of spins, and a long relaxation time. In this line, Benzyldeno-2,3-dihydro-1H-[1,3]diphosphole (BDF) derivatives have been theoretically tested for maximizing large δ andJ and minimizing the hyperfine coupling constant-A. Thus, the structures were optimized at the B3LYP/6-311G(d,p) level and showed much similarity with the experimental geometrical parameters. NMR spectroscopic parameters (δ and J) were calculated with six different DFT functionals. The method τ-HCTH/6-31G(2d) is in better agreement with the experimental data of 31P and 13C chemical shifts. While PCM-B3LYP/ccPVDZ shows a decrease on deviation between calculated and experimental values for P-P and P-C spin-spin constant coupling. The Surface Response technique was employed to rationalize how the hyperfine constant was altered with modification in chemical shifts and coupling constants values. From our findings, BDF-NO2 was the best candidate for NMR quantum computations (NMR-QC) among the studied series.