Second Harmonic Generation and Two-Photon Fluorescence as Nonlinear Optical Properties of Dipolar Mononuclear Sesquifulvalene Complexes
✍ Scribed by Hans Wong; Timo Meyer-Friedrichsen; Tony Farrell; Christoph Mecker; Jürgen Heck
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 601 KB
- Volume
- 2000
- Category
- Article
- ISSN
- 1434-1948
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✦ Synopsis
Sesquifulvalene / Sandwich complex In order to investigate nonlinear optical properties, in particular second harmonic generation (SHG) of organometallic complexes, numerous dipolar monocationic sesquifulvalene complexes of the general form [McϪZϪ C 7 H 6 ] + have been synthesised (Mc = metallocenyl), wherein the metallocenyl moiety Mc acts as an electron donor, and the tropylium cation C 7 H 6 + as an electron acceptor. The mutual electronic influence of the donor and the acceptor groups is warranted by a linking spacer Z, which is a single bond [Mc = CpFeC 5 H 4 (4a); Mc = CpRuC 5 H 4 (4b)], an unsaturated bridge containing olefins [Z = (E-CH=CH) n : n = 1, Mc = CpFeC 5 H 4 (25a); Mc = CpRuC 5 H 4 (25b); n = 2, Mc = CpFeC 5 H 4 (26); n = 3, Mc = CpFeC 5 H 4 (27)], or thiophene units [Z = 2,5-C 4 H 2 S, Mc = CpFeC 5 H 4 (28); Z = 5,5Ј-(2,2Ј-C 4 H 2 S) 2 , Mc = CpFeC 5 H 4 (29); Z = 2-(5-E-CH=CH)C 4 H 2 S, Mc = CpFeC 5 H 4 (30)]. For the salts of 4a•BF 4 , 4b•PF 6 and 25a•PF 6 X-ray structure determinations have been performed [4a•BF 4 : orthorhombic, Pnma, a = 21.75(2), b = 9.900(2), c = 6.881(3) A ˚, V = 1482.0(15) A ˚3, Z = 4; 4b•PF 6 : monoclinic, P2(1)/c, a = 8.104(3), b = 18.206(14), c = 11.228(4) A ˚, β = 107.59(3), V = 1579.1(15) A ˚3, Z = 4; 25a•PF 6 : triclinic, P1 ¯, a = 10.067(6), b = 10.496(6), c = 11.418(6) A ˚, α = 94.07(4), β = 110.96(4), γ = 102.88(5)°, V = 1083.1(11) A ˚3, Z = 2]; the solid state structures indicate an almost coplanar arrangement of the organic π-system. Cyclic voltammetry studies reveal an