Synthesis and solid state structure of an unsymmetrical triurea
作者:Xavier Garcías、Leticia M. Toledo、Julius Rebek
DOI:10.1016/0040-4039(95)01829-7
日期:1995.11
The synthesis and single crystal X-ray diffraction analysis of 1 is reported. Hydrogen bonding and solvation play an important role in the solidstatestructure of 1.
报道了1的合成和单晶X射线衍射分析。氢键和溶剂化发挥的固态结构的重要作用,1。
Substituent Effects in Pentacenes: Gaining Control over HOMO−LUMO Gaps and Photooxidative Resistances
作者:Irvinder Kaur、Wenling Jia、Ryan P. Kopreski、Selvapraba Selvarasah、Mehmet R. Dokmeci、Chandrani Pramanik、Nicol E. McGruer、Glen P. Miller
DOI:10.1021/ja804515y
日期:2008.12.3
A combined experimental and computational study of a series of substitutedpentacenes including halogenated, phenylated, silylethynylated and thiolated derivatives is presented. Experimental studies include the synthesis and characterization of six new and six known pentacenederivatives and a kinetic study of each derivative under identical photooxidative conditions. Structures, HOMO-LUMO energies
Synthesis and Assembly of New Molecular Hosts: Solvation and the Energetics of Encapsulation
作者:R. Meissner、X. Garcias、S. Mecozzi、J. Rebek
DOI:10.1021/ja962991f
日期:1997.1.1
Experimental details are given for the preparation of ''softballs'', large self-complementary molecules capable of assembly into pseudo-spherical capsules. Evidence is presented for their existence as hydrogen bonded dimers:in organic solvents, and binding affinities for the reversible encapsulation of smaller molecules of suitable size and shape are given. Studies at various temperatures result in calculated enthalpies and entropies of encapsulation that are positive; accordingly, the process is entropy driven. It is proposed that the hosts in their resting states contain two molecules of solvent such as benzene, and the encapsulation of a single large guest-the hostage-liberates the two solvents. The resulting increase in the number of free molecules gives rise to the increase in entropy observed for the exchange process. Experiments involving solvent mixtures are consistent with this rationale. Calculation of the capsule's interior volume and molecular dynamics simulations support the experimental observations, and hint at unexpected phenomena dealing with the occupancy factors of these systems.