The geometrical structures of Wells-Dawson derivatives[X-C(CH_(2)O)_(3)P_(2)M’_(3)M_(15)O_(59)]^(6-)(X=NO_(2),NH_(2),and CH_(3),M’=V and Nb,M=W and Mo)have been calculated by the density functional theory(DFT)method...The geometrical structures of Wells-Dawson derivatives[X-C(CH_(2)O)_(3)P_(2)M’_(3)M_(15)O_(59)]^(6-)(X=NO_(2),NH_(2),and CH_(3),M’=V and Nb,M=W and Mo)have been calculated by the density functional theory(DFT)method.The results show that the distances of P…P and P…C are controlled by the{M’_(3)}triads,and{M’_(3)}triads also affect the sizes of W_(6) hexagonal belts.The second-order polarizabilities and origin of nonlinear optical(NLO)properties of those clusters have been investigated by a time-dependent density functional theory(TDDFT)method.The NLO property analysis reveals that[X-C(CH_(2)O)3P_(2)V_(3)Mo_(15)O_(59)]^(6-)(X=NH_(2))anions have the largest β_(vec) values,75.064×10^(-30) esu.Grafting electron donors to POM clusters is an efficient way to improve the NLO response.The major electron transition orbitals show that the charge transfer from the organic groups to the metal atoms is responsible for the NLO properties of these polyoxometalates.展开更多
基金financial support by NSFC(20971020,21073030 and 21131001)Program for New Century Excellent Talents in University(NCET-10-318)+1 种基金Doctoral Fund of Ministry of Education of China(20100043120007)the Science and Technology Development Planning of Jilin Province(20100104 and 20100320).
文摘The geometrical structures of Wells-Dawson derivatives[X-C(CH_(2)O)_(3)P_(2)M’_(3)M_(15)O_(59)]^(6-)(X=NO_(2),NH_(2),and CH_(3),M’=V and Nb,M=W and Mo)have been calculated by the density functional theory(DFT)method.The results show that the distances of P…P and P…C are controlled by the{M’_(3)}triads,and{M’_(3)}triads also affect the sizes of W_(6) hexagonal belts.The second-order polarizabilities and origin of nonlinear optical(NLO)properties of those clusters have been investigated by a time-dependent density functional theory(TDDFT)method.The NLO property analysis reveals that[X-C(CH_(2)O)3P_(2)V_(3)Mo_(15)O_(59)]^(6-)(X=NH_(2))anions have the largest β_(vec) values,75.064×10^(-30) esu.Grafting electron donors to POM clusters is an efficient way to improve the NLO response.The major electron transition orbitals show that the charge transfer from the organic groups to the metal atoms is responsible for the NLO properties of these polyoxometalates.
