Abstract |
Fe(II) 및 Ni(II) 이온에 NH3 리간드를 배위시켜 분자역학(MM2)법으로 최소에너지를 갖는 구조를 구한 후 확장분자궤도함수(EHMO)법 및 ZINDO/1법으로 양자화학적 양을 얻어 실험적 사실과 비교 검토하였다. 즉, 팔면체인 [M(H2O)6-x(NH3)x]2+(M=Fe(II), Ni(II)(x=0,1,…,6)에서 NH3 분자가 H2O 분자와 단계적으로 치환될 때에 따른 실측리간드화열이 MO 이론으로 계산한 팔면체형인 Fe(II)및 Ni(II)착물의 양자화학적 양인 중심금속의 알짜전하, 형성엔탈피, 총결합에너지로부터 실측 리간드화열(ΔHobs)을 이론적으로 예측할 수 있는 ΔHobs=-0.2858qFe+0.8813(r=0.97), ΔHobs=-0.8981qNi+1.7929(r=0.95), ΔHobs=-0.0031Hf(Fe)+0.5725(r=0.97), ΔHobs=-0.0095Hf(Ni)+0.9193(r=0.97), ΔHobs=0.0476Ediss(Fe)+0.6434(r=0.94), ΔHobs=0.1401Ediss(Ni)+1.1393(r=0.93)인 이론식을 각각 얻었다. The correlation was investigated between the observed heat of ligation and calculated quantum chemical quantities for octahedral [M(H2O)6-x(NH3)x]2+ (M=Fe(II), Ni(II)) complexes by EHMO(Extended Huckel Molecular Orbital) and ZINDO/1(Zemer's Intermediate Neglected of Differential Overlap)method. The net charge of Fe2+ and Ni2+ ion of octahedral [M(H2O)6-x(NH3)x]2+(M=Fe(II), Ni(II)) complexes(x=O, 1, …, 6) decreased with substituting NH3 for H2O molecules. It has found that a good correlation exists between the observed heat of ligation and the calculated quantum chemical quantities such as net charge of central atom, enthalpy of formation, and total dissociation energy. From this finding, we have obtained the following semiempirical linear equation ΔHobs=-0.2858qFe+0.8813(r=0.97), ΔHobs=-0.8981qNi+1.7929(r=0.95), ΔHobs=-0.0031Hf(Fe)+0.5725(r=0.97), ΔHobs=-0.0095Hf(Ni)+0.9193(r=0.97), ΔHobs=0.0476Ediss(Fe)+0.6434(r=0.94), ΔHobs=0.1401Ediss(Ni)+1.1393(r=0.93) |
