Mononuclear and Polynuclear Chelates of Picolinoyldithiocarbazate.
作者:Tawfik H. RAKHA、Magdy M. BEKHEIT
DOI:10.1248/cpb.48.914
日期:——
Mononuclear and polynuclear chelates of potassium picolinoyldithiocarbazate (KHPcDC) with Mn(II), Fe(III), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), Pd(II) and U(VI)O2 have been prepared and characterized by chemical and thermal (TG, DTG, DTA) analyses, molar conductivities, spectral (UV-Visible, IR, NMR, ESR) and magnetic moment measurements. The molar conductivities of the complexes lie in the non-electrolyte range whilst KHPcDC is a 1 : 1 electrolyte. Changes in selected vibrational absorption of the ligand upon coordination indicate that KHPcDC behaves as monoanionic and coordinates in a bidentate, tridentate and/or bridging tetradentate manner. Trans-form structure is proposed for [Pd(HPcDC)2]·2H2O and [Cd(HPcDC)2] complexes on the basis of NMR data. An octahedral structure is proposed for Fe(III), Fe(II) and Ni(II) complexes, a square-planar structure for Co(II) and Pd(II) complexes and a tetragonally distorted octahedral structure for the Cu(II) chelate on the basis of spectroscopic and magnetic data. The ligand field parameters (B, Dq, β) for the Fe(III) and Ni(II) chelates were calculated. TG, DTG and DTA studies support the different modes of chelation of KHPcDC. The solid metal acetate chelates have a unique decomposition exotherm profile which can be used as a rapid and sensitive tool for the detection of acetate-containing complexes.
通过化学和热学(TG、DTG、DTA)分析、摩尔电导率、光谱(紫外-可见)和 U(VI)O2,制备了吡啶酰基二硫代卡巴肼钾(KHPcDC)与锰(II)、铁(III)、铁(II)、钴(II)、镍(II)、铜(II)、锌(II)、镉(II)、汞(II)的单核和多核螯合物、钯(II)和 U(VI)O2,并通过化学和热学(TG、DTG、DTA)分析、摩尔电导率、光谱(紫外-可见光、红外、核磁共振、ESR)和磁矩测量进行了表征。复合物的摩尔电导率在非电解质范围内,而 KHPcDC 是 1 : 1 的电解质。配体在配位时所选择的振动吸收变化表明,KHPcDC 表现为单阴离子,并以双齿、三齿和/或桥接四齿方式配位。根据核磁共振数据,提出了 [Pd(HPcDC)2]-2H2O 和 [Cd(HPcDC)2] 复合物的反式结构。根据光谱和磁性数据,提出了 Fe(III)、Fe(II) 和 Ni(II) 复合物的八面体结构,Co(II) 和 Pd(II) 复合物的方平面结构,以及 Cu(II) 螯合物的四方扭曲八面体结构。计算了 Fe(III) 和 Ni(II) 螯合物的配体场参数(B、Dq、β)。TG、DTG 和 DTA 研究证实了 KHPcDC 不同的螯合模式。固态金属醋酸盐螯合物具有独特的分解放热曲线,可用作检测含醋酸盐络合物的快速灵敏工具。