Department of Chemistry, The University of Burdwan, Golapbag, Burdwan 713 104, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2012 Jul;93:384-9. doi: 10.1016/j.saa.2012.01.079. Epub 2012 Feb 7.
The present paper reports the spectroscopic investigations on non-covalent interaction of fullerenes C(60) and C(70) with a designed trihomocalix[6]arene (2) in toluene. UV-vis studies reveal appreciable ground state interaction between fullerenes and 2. Jobs method of continuous variation establishes 1:1 stoichiometry for fullerene-2 complexes. Binding constant (K) data reveals that 2 binds C(70) more strongly compared to C(60), i.e. K(C60-2)-47,540 dm(3)mol(-1) and K(C70-2)-86,360 dm(3)mol(-1). Proton NMR studies provide very good support in favor of strong binding between C(70) and 2. Estimation of solvent reorganization energy (R(S)) evokes that C(70)-2 complex is stabilized more compared to C(60)-2 complex as R(S(C60-2))- -1.162 eV and R(S(C70-2))- -1.244eV. Semiempirical calculations at third parametric level of theory in vacuo evoke the single projection structures of the fullerene-2 complexes and interpret the stability difference between C(60) and C(70) complexes of 2 in terms of enthalpies of formation values.
本文报道了富勒烯 C(60) 和 C(70) 与设计的三杂杯[6]芳烃 (2) 在甲苯中非共价相互作用的光谱研究。紫外-可见研究表明富勒烯与 2 之间存在显著的基态相互作用。连续变化的 Jobs 法确定了富勒烯-2 配合物的 1:1 化学计量比。结合常数 (K) 数据表明，2 与 C(70) 的结合比与 C(60) 的结合更强，即 K(C60-2)-47,540 dm(3)mol(-1) 和 K(C70-2)-86,360 dm(3)mol(-1)。质子 NMR 研究为 C(70) 和 2 之间的强结合提供了很好的支持。溶剂重排能 (R(S)) 的估算表明，与 C(60)-2 配合物相比，C(70)-2 配合物更稳定，因为 R(S(C60-2))- -1.162 eV 和 R(S(C70-2))- -1.244eV。在真空第三参数水平理论的半经验计算中，提出了富勒烯-2 配合物的单投影结构，并根据形成焓值解释了 2 中 C(60)和 C(70)配合物稳定性差异。
