Conjugated compounds with

Cyclopropyl ketones (29) behave as weakly conjugated compounds, with significant orbital overlap between one ty-bond (or sometimes two) of the cyclopropane ring and the jr-orbital of the carbonyl group (p. 242). The three-membered ring is reduced by lithium in liquid ammonia, with rupture of whichever cr-bond most effectively overlaps the carbonyl tt-orbital [280]. The reduction probably involves transfer of an electron to the jS -carbon atom of this cr-bond, so that conjugative overlap can be maintained during a smooth transition to the species (30) which is both a carbanion and a resonance-stabilised enolate radical. A second electron trans-... 

A cyclic, planar, completely conjugated compound with 4n + 2 tc electrons. 

Stilbazole derivatives and r-conjugated compounds with a pyridine unit have been extensively studied for a wide range of applications. The grafting of phosphonic acid-derived stilbazole (4-(2-pyridin-4-yl-vinylj-benzylphosphonic acid) on Sn02 or... 

In summary, silole-based oligomers present an interesting class of organosilicon a-7t conjugated compounds with unique electronic and optical properties. A low lying LUMO level can be further adjusted by appropriate combination with other... 

Peptides and proteins form a wide range of conjugated compounds with carbohydrates. Carbohydrates are present mostly as linear or branched oligosaccharides. In some conjugated compounds the properties of peptide (protein) predominate, therefore these complex saccharides include ... 

Pentalene (135) and acepentalene (137) are antiaromatic cross-conjugated compounds with two or three fulvene subunits. According to theoretical calculations [142-147], 135 and 137 are unstable species [147, 148] but can be ligands in transition metal complexes. The respective anions, the planar 136 [149, 150] and the slightly bowl-shaped 138 [151, 152], can be generated by deprotonation of a dihydropentalene or by treatment of4,7-bis(trimethylstannyl)-4,7-dihydroacepentalene with methyllithium at -60 °C (Scheme 10.48). 

The oligo(l,4-phenylene)s (OP) comply also with a linear rdation L(n) however, as soon as cross-conjugated compounds with meta linked benzene rings are considered, L becomes meaningless, because a variety of conformers of different shape exists. 

Although tricyanovinylthiophene derivatives (30) had been previously used as the acceptor moiety in donor-acceptor 7c-extended conjugated compounds with nonlinear optical properties [51], isolated tricyanovinylthiophenes had not been examined as acceptors for the preparation of CT complexes or CT salts. These easily soluble acceptors showed a slight deviation from planarity, the angle defined by the least-squares plane formed by the thiophene ring and the tricyanovinyl substituent being 9(1)° (Figure 1.8). 

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