We have theoretically investigated two series of cyclometalated Pt(Ⅱ) complexes,a series [Pt(C,N,N) Cl] and b series [Pt(C,N,Npyrazolyl) Cl].The geometrical and electronic structures are calculated at the ECP60MWB//6-31G*(H,C,Cl,N,S) basis set level using DFT method;one-photon absorption(OPA) properties are calculated by using both TDDFT and ZINDO methods and two-photon absorption(TPA) properties are obtained with the ZINDO/SOS method.The resonance integrals parameters(βsp and βd) for Pt are adjusted to -1 and -28.5 eV,respectively,to make max OPA wavelength calculated by ZINDO closest to the experimental data and TDDFT results.The calculated results indicate the molecule 2b([Pt(Cnaphthyl,N,Npyrazolyl) Cl]) has the biggest potential as outstanding TPA materials because(i) the TPA properties of b series are more outstanding in IR wavelength range,the molecules in b series have good transparencies and possess 1-pyrazolyl-NH that is also available for another metal coordination(e.g.,dimerization) and chemical interactions;(ii) when C is Cnaphthyl in the C,N,N ligand of cyclometalated Pt(Ⅱ) complexes,the molecules have the best conjugation effect and the best TPA properties.
