First Hyperpolarizabilities of Manganese(I)−Chromium(0) Sesquifulvalene Complexes

Intramolecular charge transfer and first-order hyperpolarizability of planar and twisted sesquifulvalenes

“…Sesquifulvalene is an important ligand in constituting organometallic compounds where the cyclopentadienyl and cycloheptatrienyl fragments act as strong electron-donating and electron-withdrawing groups, respectively. 15,16 It has also been observed experimentally that sesquifulvalene complexes exhibit unusually large NLO properties, and that their b values are among the highest ever measured for organometallic NLO chromophores. [15][16][17][18] Although sesquifulvene does not contain substituents, such large NLO responses could be related to the '' sudden polarization ''.…”

“…15,16 It has also been observed experimentally that sesquifulvalene complexes exhibit unusually large NLO properties, and that their b values are among the highest ever measured for organometallic NLO chromophores. [15][16][17][18] Although sesquifulvene does not contain substituents, such large NLO responses could be related to the '' sudden polarization ''. Both planar (I, Fig.…”

“…1) structures of sesquifulvalene have been observed in metallic complexes. 15 The presence of sesquifulvalene under different conformations results from the interplay between antagonistic effects. On the one hand electron delocalization generally favors the planar conformation of a bicyclic molecule whereas, on the other hand, the repulsion between well-positioned substituents (as well as hydrogen atoms) induces a torsion.…”

Donor−Acceptor Interaction in Cationic Archetype Mono- and Dinuclear Sesquifulvalene Complexes [(η5-C5H5)Fe{µ-(η5-C5H4)(η7-C7H6)}M′L′]n+ (n = 1, 2)

“…Cyclic voltammetry studies were conducted on all of the sesquifulvalene complexes as well as for the unsubstituted tropylium cation (7) and the corresponding mononuclear complexes [(η 7 -C 7 H 7 )MЈLЈ] ϩ [MЈLЈ ϭ Cr(CO) 3 (8), Ru(η 5 -C 5 H 5 ) ϩ (9), Ru(η 5 -C 5 Me 5 ) ϩ (10)]. Electrochemical studies on 7, [12] 8, [13] and 9 [11a] have already been described.…”

Insight into the structures of [M(C5H4I)(CO)3] and [M2(C12H8)(CO)6] (M= Mn and Re) containing strong I...O and π(CO)–π(CO) interactions

“…In contrast, the only analogous compound found in the literature, viz. [(CO) 3 Mn(C 5 H 4 )C C(C 7 H 5 )Cr(CO) 3 ]-BF 4 , possesses a syn-facial (cisoid) conformation of M(CO) 3 moieties, due to the formation of strong attractive intermolecular (CO)-(CO) interactions with a perpendicular packing motif (Tamm et al, 2000). The conformation of (CO) 3 M(C 5 H 4 ) moieties thus appears to depend, at least in part, on the type of (CO)-(CO) interactions formed.…”