Quantitative Relationship Between ~13(C) Nuclear Magnelic Resonance Chemical Shift and Structural Parameters of Acyclic Alcohol
A newly developed topological vector of atom YC,equilibrium electro-negativity of atom qe,molecular structural information parameter[NiH(i=α,β)] and γ calibration parameter were used to describe the local chemical microenvironment of 63 acyclic alcoholic compounds.Quantitative structural spectrum relationships(QSSR) was systematically made on relationship between 13 C NMR chemical shifts of 353 carbon atoms and their molecular structure descriptors.By partial least square regression(PLS),the statistical results indicated that the model correlation coefficient and standard error were 0.9915 and 2.4827,respectively.And the average absolute error was only 2.01×10-6 between the calculated and experimental chemical shifts for 353 carbon atoms.To validate the estimation stability for internal samples and the predictive capability for external samples of resulting models,leave-molecule-out(LMO) cross validation(CV) and external validation were performed.Compared with the reported result,not only the number of descriptors employed in this study was much fewer,but also the calculation was much easier.