摘要
应用DFT方法对二苯基亚砜(DPSO)和二己基亚砜(DHSO)的钯"配合物进行了理论计算。结果表明中心金属钯与亚砜之间存在d-(Ⅱ)*反馈键,而且二苯基亚砜钯(II)配合物中的π反馈键比二己基亚砜钯"配合物强,即亚砜的取代基对其钯"配合物的π反馈键有显著的影响。以BHandH/6-31+G**(Pd,3-21G*)//BHandH/6-31G*(Pd,3-21G*)方法对相应的亚砜钯"配合物进行单点计算时,配合物trans-PdCl_2(DPSO)_2的π反馈键轨道能为-10.695eV,而trans-PdCl_2(DHSO)_2的π反馈键轨道能量为-10.320eV。利用电子给体NH_3或电子受体CO配位体置换亚砜钯"配合物里的一个亚砜配体后,Pd"-DHSO配合物的Pd-S配位键长的变化明显小于Pd-DPSO配合物的Pd-S配位键长变化值,进一步说明在Pd-DPSO配合物中的π反馈效应强于相应的Pd-DHSO配合物。
Theoretical calculations on di-phenyl sulfoxide （DPSO） and di-n-hexyl sulfoxide （DHSO） Pd（Ⅱ） complexes had been carried out by DFT method, d-π back-donation bond could be found in these sulfoxide Pd（Ⅱ） complexes, and π back-donation bond in DPSO-Pd （Ⅱ） complex is stronger than that in DHSO-Pd（Ⅱ） complex, indicating the substituent of sulfoxide ligand can influence Pd-sulfoxide d-π＊ back-donation interaction significantly. By BHandH/6-31＋G^＊＊ （Pd, 3-21G^＊）//BHandH/6-31G^＊ （Pd, 3-21G^＊） method, the calculated d-π＊ back-binding orbital energy of trans-PdC12 （DPSO）2 is -10.695 eV, which is slightly lower than that of trans-PdCl2 （DHSO）2 （-10.320 eV）. The 7r back-donation effect on the Pd（Ⅱ）-S bond lengths were further examined by calculations on model complexes [trans-PdCl2（CO）DHSO], [trans-PdCl2（NH3）DHSO], [trans-PdCl2（CO）DPSO] and [trans-PdCl2（NH3）DPSO] which contains σ-donor（NH3） or π-acceptor（CO） ligands. The change of Pd-S bond lengths in DHSO-Pd（Ⅱ） complexes is obviously less than that in DPSO-Pd（II） complexes after the ligand substitution, suggesting DPSO-Pd（Ⅱ） complex has a stronger π back-donation interaction than DHSO-Pd（Ⅱ） complex.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2007年第5期785-790,共6页
Chinese Journal of Inorganic Chemistry
基金
国家自然科学基金资助项目(No.20572027)。
