Secondary harmonic generators

Dimethyl /V-(3-methyl-2(3//)-benzothiazol-2-ylidene)malonate was used as a secondary harmonic generating agent at the production of nonlinear optical materials [89JAP(K)205130]. 

After a presentation of various methods of direct electrochemicai systhesis (D.G. Tuck) the redox properties of those types of complexes and their relationships with structure and reactivity have been discussed. In particular, the parameterisation of metal centred redox couples has been evaluated (A.B.P. Lever), synthetic, structural and electronic consequences of electron-transfer reactions have been presented (M. Gross and K. Wieghardt) and redox-active complexes discussed (J.A. McCleverty) as components of secondary harmonic generators in non-linear optical materials. 

It may not be a coincidence that nitroanilines have been a useful class of compounds for second harmonic generation (12-13). They naturally associate into polar arrays, which are manifested in their crystal structures. The important question is whether or not these polar arrays are likely to bias the resulting crystal structures to be acentric. Although we do not have large enough data sets to make a statistically convincing case, from a set of 32 primary and secondary nitroanilines and analogs, about 40% of their crystal structures are acentric. These compounds are all capable of... 

Fig. 2.2. Experimental setup (as used for the investigations on NasB). An argon ion laser (ps mode-locked fs all lines, visible) pumps either a femtosecond laser system (a) (OPO synchronously pumped optical parametric oscillator SHG second-harmonic generator) or a picosecond laser system (b) (taken from [178]). The pulse duration and spectral width of the laser pulses are measured by an autocorrelator (A) and a spectrometer (S) respectively. A Michelson arrangement allows the probe pulses to be delayed At) with respect to the pump pulses. A quadrupole mass filter (QMS) enables the selection of the ensemble of investigated molecules ionized by a pump probe cycle. A secondary electron multiplier (SEM) detects the intensity I of the ions as a function of the delay time At. A Langmuir-Taylor detector (LTD) measures the total intensity /o of the cluster beam. The ratio I/Iq as a function of the delay time At is called the real-time spectrum...

Surface-extended X-ray absorption fine structure (analysis) spectroscopy Sum frequency generation Second harmonic generation Surface ionization Secondary ion mass spectroscopy Subtractively normalized interfacial Fourier transform infrared spectroscopy Single potential alteration infrared (spectroscopy)... 

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