Broad Molecular Ribbons of Nanometer Size Composed of Biphenyl Units
摘要:
The new tetrafunctionalized biphenyl key building blocks 16 and 39 led, for the first time, to the hitherto broadest molecular ribbons that contain biphenyl units in a transverse arrangement by iterative synthetic methods. The length and breadth of the molecular ribbons, as single chemical entities, are diversified. They can be used as cyclization precursors in the synthesis of long molecular tubes of type 2 with a large diameter. The solubility and the host-guest behavior (clathrate formation with benzene, dimethylformamide, and dichloromethane) of these nanometer-size molecular ribbons were optimized by the introduction of various side chains (benzenesulfonamide, 4-toluenesulfonamide, and 4-terf-butylbenzenesulfonamide groups) into the skeleton of the ribbons. New 14-, 15-, and 16-membered model ring systems (compounds 20a, 22a, and 24 respectively) were synthesized in order to examine the constitution of the 16-membered diaza[3.3]-phane 18a. Nanometer-size tube-shaped molecules 7a, 7b and 8 were obtained by cyclization of tetrafunctionalized molecular ribbons with the biphenyl building block. The constitution and conformation of the molecular ribbons and belts were proven by NOE experiments and X-ray analyses.
Broad Molecular Ribbons of Nanometer Size Composed of Biphenyl Units
摘要:
The new tetrafunctionalized biphenyl key building blocks 16 and 39 led, for the first time, to the hitherto broadest molecular ribbons that contain biphenyl units in a transverse arrangement by iterative synthetic methods. The length and breadth of the molecular ribbons, as single chemical entities, are diversified. They can be used as cyclization precursors in the synthesis of long molecular tubes of type 2 with a large diameter. The solubility and the host-guest behavior (clathrate formation with benzene, dimethylformamide, and dichloromethane) of these nanometer-size molecular ribbons were optimized by the introduction of various side chains (benzenesulfonamide, 4-toluenesulfonamide, and 4-terf-butylbenzenesulfonamide groups) into the skeleton of the ribbons. New 14-, 15-, and 16-membered model ring systems (compounds 20a, 22a, and 24 respectively) were synthesized in order to examine the constitution of the 16-membered diaza[3.3]-phane 18a. Nanometer-size tube-shaped molecules 7a, 7b and 8 were obtained by cyclization of tetrafunctionalized molecular ribbons with the biphenyl building block. The constitution and conformation of the molecular ribbons and belts were proven by NOE experiments and X-ray analyses.