principle that most of us are linked by short chains of acquaintances — was first investigated as a question in sociology and is a feature of a range of networks arising in nature and technology. Experimental study of the phenomenon revealed that it has two fundamental components: first, such short chains are ubiquitous, and second, individuals operating with purely local information are very a...

A monocationic plug-socket connector that is composed, at the molecular level, of three components, (1) a secondary dialkylammonium center (CH2NH2+CH2), which can play the role of a plug toward dibenzo[24]crown-8 (DB24C8), (2) a rigid and conducting biphenyl spacer, and (3) 1,4-benzo-1,5-naphtho[36]crown-10 (BN36C10), capable of playing the role of a socket toward a 4,4'-bipyridinium dicationic...

A series of crown ether complexes of potassium quinolin-8-olates were synthesized and characterized. Catalysis of these complexes towards the ring-opening polymerization of rac-lactide was evaluated. The crown ether complexes of potassium quinolin-8-olate and potassium 2-methylquinolin-8-olate exhibited high catalytic activity and good molecular weight control. The 18-crown-6 complex of potassi...

The title salt, [K(C(12)H(24)O(6))][Fe(C(8)H(12))(C(10)H(8))], is the only known naphthalene complex containing iron in a formally negative oxidation state. Each (naphthalene)(1,5-cod)ferrate(-I) anion is in contact with one (18-crown-6)potassium cation via K⋯C contacts to the outer four carbon atoms of the naphthalene ligand (cod = 1,5-cyclo-octa-diene, 18-crown-6 = 1,4,7,10,13,16-hexa-oxacycl...

Rotaxanes can have topological isomers because of their mechanically interlocked axle and wheel components. Directional are formed when the rotaxanes constructed using an asymmetric a three-dimensional non-symmetrical wheel. In this work, directional [2]rotaxanes were synthesised lariat dibenzo-24-crown-8 ether as component sec-ammonium salt axle. Control over isomer ratio was achieved, demonst...

IN THE TITLE COMPOUND (SYSTEMATIC NAME 17-formyl-2,5,8,11,14-penta-oxabicyclo-[13.4.0]nona-deca-15,17,19-triene), C(15)H(20)O(6), the 15-crown-5 ring adopts a twisted conformation. The formyl group is coplanar with the benzene ring. The crystal packing is stabilized by C-H⋯O inter-actions involving the C=O group and ether O atoms as acceptors and methyl-ene CH groups as donors.