Cubic NLO properties

The cubic NLO properties of Ru11 tris-(a-diimine) complexes have been investigated only relatively recently by Ji and co-workers using 540 nm Z-scan all of the complexes studied exhibit both NLO absorption and SDF behavior.135-138 The large and 7 values of complexes such as (73) depend on the position of the -N02 group in the order 4- > 2- > 3-.135 Also, the NLO responses decrease on deprotonation of the imidazolyl nitrogens (although this effect is only... 

Blau and co-workers first reported observations of RSA in toluene solutions of Zn11 or Co11 meso-tetraphenylporphyrins with 80 ps pulses at 532 nm,147 and also proposed a theoretical mechanistic description for the cubic NLO properties of these complexes.148 RSA in Fe11 meso-tetraphenylporphyrin was later described by Fei et al.149 Other early 532 nm DFWM studies150-152 involve complexes of tetrabenzoporphyrins which were found in THF to display (3) values... 

Torres and co-workers have investigated the cubic NLO properties of various metallotriazo-lehemiporphyrazines.190-194 Early THG studies at 1,340 nm and 1,907 nm with CHCI3 solutions show that metal ions with partially filled d-shells enhance 7 when compared to the uncomplexed macrocycles.190,191 However, later 1,064 nm THG studies with LB films of some Co11 complexes indicate that metallation has no significant effects on the NLO responses.192 More recently,... 

Many studies dealing with the cubic NLO properties of MPcs have been reported since 1990, and these will be discussed only briefly here, focusing on the research of the following leaders in this field Agullo-Lopez,220,225-232 Nalwa,196,233-239 Perry,240-248 Shirk,249-265 Hanack,239,264-271 Wada,272-284 Heflin,285-290 Yamashita,291-297 and Fang.298-302... 

NIR region (see Chapter 9.13), complexes of 1,2-dithiolene (DT) and related ligands have attracted considerable attention for their (largely cubic) NLO properties. The complex (156) (a.k.a. BDN) is a highly photochemically stable, saturable absorber and has hence found extensive applications in laser Q-switching. The cubic NLO properties of (156) have been studied by DFWM148,403-407 and more recently, Z-scan.408 Time-resolved DFWM has been applied to square planar Co, Ni, Cu, or Pt complexes of 1,2-benzenedithiolate (BDT) or 1,2-aminobenzenethiolate ligands by Lindle and co-workers.409,410... 

Winter, Underhill, and co-workers have published extensively on the cubic NLO properties of complexes of DT and related ligands,411 22 particularly those containing formally Ni11 centers. For example, time-resolved 1,064 nm DFWM was used to obtain resonantly enhanced values for group 10 complexes such as (157).411 15 The smaller of (157) compared with (156) is largely due to resonance effects since the absorption maximum of (157) is somewhat removed from the laser fundamental. However, figures of merit derived from measurements of 2 and linear and two-photon absorption (TPA) coefficients show that low optical losses render complexes such as (157) superior to (156)413 for potential all-optical switching applications.411 14... 

Studies on the cubic NLO properties of Mo/W-S/Se-Cu/Ag clusters have been reviewed,539-541 and some related species which contain pseudo-square planar Pd11 centers instead of CuVAg1 have also been investigated.542-545 However, such complexes, e.g., the hexanuclear windmill cluster... 

Several studies have addressed the cubic NLO properties of salts of heteropolymolybdate/ tungstate cluster anions.360,557-561 The tetraanion in a-H4SiW12O40,4HMPA,2H2O (HMPA= hexamethylphosphoramide) has a Keggin structure which has idealized Td point symmetry... 

Particularly notable reports from McDonagh et al. describe the molecular quadratic and cubic NLO properties of the 3-fold symmetric octupolar Ru" complexes 43 and 44 [104, 105]. According to the results of 1064nm HRS experiments, moving from the dipolar complex 45 to its octupolar analogue 44 produces... 

NLO Molecules and Materials Based on Organometallics Cubic NLO Properties... 

Determination of cubic NLO properties of molecules is most often carried out in liquid solutions, but it is possible to use solid samples made by (for example) dispersing the chromophore in a host polymer, or as thin hlms of the pure compound under investigation, if the optical quality of the samples is sufficiently high. Depending on the method of measurement, the real and imaginary parts of y (or 2 and (I2) may be determined, but in some cases only the modulus is measured. The experimental techniques have been described in detail elsewhere [13], so only a short description of them is given here. 

---