摘要
本文对二氯甲烷溶剂中咪唑(Im)与氯代(对位取代四苯基)卟啉铁(Ⅲ)[Fe(p-X)TPPCl,X=Cl,H,CH_3,OCH_3]的轴向配位反应(1)进行了研究.用光谱法测得了反应(1)的平衡常数,并对反应物和产Fe(p-X)TPPCl+2Im(?)[Fe(p-X)TPPIm_2]+Cl^-物的电子光谱、FeHTPPCl和[FeHTPPIm_2]^+Cl^-的电子自旋共振谱和穆斯堡尔谱进行了测量。研究了取代基效应和轴向配体的影响。
A thermodynamic study is reported for the axial coordination of para-substituted tetraphenylporphinatoiron(Ⅲ ) chloride [Fe(p-X)TPPCl, X = C1, H, CH3, OCH3] with imidazolc(Im) in dichloromethane.
Fe(p-X)TPPCl+2Im β [FeG7-X)TPP(Im)J+Cr (1)
Not only the equilibrium constant(β) of reaction (1) by spectral technique, but also the visible absorption spectra of reactants and products, and ESR spectra and Mossbauer spectra of FeHTPPCl and [FeHTPP(Im)]+Cl- were measured. The standard change of molar enthalpy (ΔH m) and standard change of molar entropy(ΔS m) of reaction(1) were calculated. The experimental results showed that:
l.ΔH m and ΔS m of reaction(1) are negative values.
2. The spin of the iron(Ⅲ) in reactants is s=5 / 2 and in products is s= 1 / 2.
3. The electron-donating substituents make the bathochromic shift of the charge transfer bands and the increase of the oscillator strength(f) for Fe(p-X)TPPCl.
4. The stronger the electron-donating ability,of substituents, the larger the equilibrium constants are. 5. It is found that linear relationships exist between following pairs: ΔH m and the Hammett constant δ; lnβ and δ; ν of CT band and δ; f of CTband and δ.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
1991年第2期153-159,共7页
Chinese Journal of Inorganic Chemistry
基金
国家科学基金资助的课题
关键词
铁
IM
TPPCl
配位反应
热力学
para-substituted tetraphenylporphinatoiron(Ⅲ) chloride, equilibrium constant UV-Vis spectra ESR spectra Mossbauer spectra
