Aromatic π-Systems More Curved Than C60. The Complete Family of All Indenocorannulenes Synthesized by Iterative Microwave-Assisted Intramolecular Arylations
摘要:
Syntheses and X-ray crystal structures are reported for all seven members of the indenocorannulene family, comprising indenocorannulene, both isomers of diindenocorannulene, both isomers of triindenocorannulene, tetraindenocorannulene, and pentaindenocorannulene. With each additional indenoannulation, the pyramidalization of the trigonal carbon atoms at the hub of the corannulene increases. Five of the seven indenocorannulenes contain carbon atoms at the hub that are actually more pyramidalized than the carbon atoms of C-60. This work demonstrates, for the first time, that extended pi-systems with curvatures exceeding those of the most curved stable fullerenes and carbon nanotubes can be prepared by ordinary laboratory methods in solution, without recourse to high-temperature gas phase methods, such as flash vacuum pyrolysis. This proof of principle presages the days when scientists will be able to synthesize isomerically pure fullerenes and single-chirality nanotubes by well-understood, controlled chemical methods. Pentaindenocorannulene, itself, represents an attractive precursor to the C-5v end-cap of an all-carbon, single-walled, "armchair' [5,5]nanotube.
Reduction of Bowl-Shaped Hydrocarbons: Dianions and Tetraanions of Annelated Corannulenes
作者:Ivan Aprahamian、Dorin V. Preda、Mihail Bancu、Anthony P. Belanger、Tuvia Sheradsky、Lawrence T. Scott、Mordecai Rabinovitz
DOI:10.1021/jo051949c
日期:2006.1.1
with lithium, the exception being systems that can stabilize the tetraanion with lithium by special means, such as aggregation or dimerization. One such system is cyclopenta[bc]corannulene (acecorannulylene), which gives a coordinativedimer that consists of two cyclopentacorannulene tetraanions, bound together in a convex−convex fashion by lithium cations. The points of contact in this dimer are two
使用锂和钾金属还原了几种退火的邻苯二环戊二烯衍生物。研究发现,去核作用通过改变电荷分布而影响香兰素的环戊烯特性。与六元环退火的衍生物的二价阴离子比corannulene二价阴离子具有更少的年环特性和更少的顺性。这种作用在周围的Corannulenes中更加明显。-与五元环退火。还原过程中使用的碱金属对结果有很大影响,特别是对还原度有很大影响。大多数衍生物仅通过钾而不是锂被还原为四阴离子,例外的是可以通过特殊方式(例如聚集或二聚)稳定四价阴离子的体系。一个这样的系统是环戊四烯[ bc ] corannulene(acecorannulylene),它给出一个配位二聚体,该二聚体由两个环戊四烯环戊四阴离子通过锂阳离子以凸-凸的方式结合在一起。在该二聚体中的接触点是来自每个环戊四烯环烯单元的两个再杂化的碳,它们被两个锂阳离子桥接在一起。
Aromatic π-Systems More Curved Than C<sub>60</sub>. The Complete Family of All Indenocorannulenes Synthesized by Iterative Microwave-Assisted Intramolecular Arylations
作者:Brian D. Steinberg、Edward A. Jackson、Alexander S. Filatov、Atsushi Wakamiya、Marina A. Petrukhina、Lawrence T. Scott
DOI:10.1021/ja9031852
日期:2009.8.5
Syntheses and X-ray crystal structures are reported for all seven members of the indenocorannulene family, comprising indenocorannulene, both isomers of diindenocorannulene, both isomers of triindenocorannulene, tetraindenocorannulene, and pentaindenocorannulene. With each additional indenoannulation, the pyramidalization of the trigonal carbon atoms at the hub of the corannulene increases. Five of the seven indenocorannulenes contain carbon atoms at the hub that are actually more pyramidalized than the carbon atoms of C-60. This work demonstrates, for the first time, that extended pi-systems with curvatures exceeding those of the most curved stable fullerenes and carbon nanotubes can be prepared by ordinary laboratory methods in solution, without recourse to high-temperature gas phase methods, such as flash vacuum pyrolysis. This proof of principle presages the days when scientists will be able to synthesize isomerically pure fullerenes and single-chirality nanotubes by well-understood, controlled chemical methods. Pentaindenocorannulene, itself, represents an attractive precursor to the C-5v end-cap of an all-carbon, single-walled, "armchair' [5,5]nanotube.