物理化学学报 >> 1986, Vol. 2 >> Issue (05): 452-456.doi: 10.3866/PKU.WHXB19860510

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配合物的生成热与配位体的质子化热之间的直线焓关系——Ⅲ、铜(Ⅱ)-2,2-联吡啶-, 铜(Ⅱ)-邻菲咯啉-N-(间位取代苯基)氨基乙酸三元体系

陈荣悌; 林华宽; 古宗信   

  1. 南开大学化学系
  • 收稿日期:1985-05-28 修回日期:1986-02-03 发布日期:1986-10-15

LINEAR ENTHALPY RELATIONSHIPS BETWEEN HEATS OF FORMATION OF COMPLEX COMPOUNDS AND HEATS OF LIGANDS——Ⅲ. COPPER (Ⅱ) - 2,2′-BIPYRIDYL-COPPER (Ⅱ)-PHENANTHROLINE-N-(meta-SUBSTITUTED PHENYL) GLYCINES TERNARY SYSTEMS

Chen Rongdi; Lin Huakuan; Gu Zongxin   

  1. Department of Chemistry; Nankai University; Tianjin
  • Received:1985-05-28 Revised:1986-02-03 Published:1986-10-15

Abstract: The heats of formation of ternary complex compounds formed of copper(Ⅱ) with 2,2′-bipyridyl or 1,10-phenanthroline and N-(meta-substituted phenyl)glycines have been determinated by calorimatric method at 25 ℃ and Ⅰ=0.1 molL~(-1) (NaClO_4) in 30%(V/V) ethanol solution. By utilizing the data for the protonation of N-(meta-substituted phenyl) glycines determined previously and coupled with the heats of formation of ternary complex compounds, a linear enthalpy relationship: △H_M=Q-β△H_(L1) (r>0.99) with a nogative slope was obtained. In addition linear entropy relationships were also found to exist between the entropy changes on formation of ternary complex compounds and protonation of the second ligands.
The straight lines have approximately the same but negative slopes. The existence of negative slopes for linear enthalpy relationships would imply electrostatic interactions not important in the formation of thernary complex comounds, while back π bonding formation between metal ion and the first ligand and CFSE as well seem to play a significant role. Whereas negative linear entropy relationships might be accounted for by the change of entropy in configuration while the entropy of chelation and of solvation are almost parallel.