Photoinduced second harmonic generation studies on Tris(thiourea)copper(I) perchlorate Cu(SC(NH₂)₂)₃(ClO₄)

Abstract

We have established a possibility to obtain the photoinduced optical second harmonic generation in the initially centrosymmetric single crystals of tris(thiourea)copper(I) perchlorate crystallized in the monoclinic system with the space group P2 1 /c. The second-order susceptibility of the investigated crystal was measured by inducing the crystal by external laser field. The results obtained are interesting and discussed in detail. We have established that the optical second harmonic generation achieves its maximum (about 0.84 pm/V) at photoinducing power density about 1430 kW/cm 2 for the fundamental wavelength 1064 nm. The maximal output second harmonic generation (SHG) was achieved at an angle of about 35°b etween the pumping and fundamental power beam's polarizations. Such maximum may be a consequence of a competition between the so formed anharmonic photothermal expansions and the thermal destruction that occurred because of the heating of the crystal surfaces. Our independent verifications have shown that the photoinduced surfaces were heated up to 8-12°C. This may cause occurrence of photothermal relaxation processes. The output SHG exists only immediately after the act of photoinduction. The obtained dependences are caused by specific features of the Raman spectra of the investigated crystals.

Cu(I) hybrid inorganic–organic materials with intriguing stimuli responsive and optoelectronic properties

“…We comment here, on a very peculiar study performed on a single crystal in which asymmetry was generated by photoinduction produced by applying an external laser field. Krishnakumar et al, [182] reported the synthesis and the NLO properties of single crystal of Cu(SC(NH 2 ) 2 ) 3 (ClO 4 ), 144, prepared by reaction of Cu(ClO 4 ) 2 with thiourea, belonging to monoclinic centrosymmetric space group. To observe SHG, a polarized UV laser (337 nm) was applied to generate a charge density noncentrosymmetry due to polarization of the medium.…”

Solvothermal synthesis, crystal structure, and second-order nonlinear optical properties of a new noncentrosymmetric gallium-organic framework material, [N(C3H7)4]3Ga3[C6H3(CO2)3]4

“…Thus far, most of the metal cations including main group, transition, rare-earth, lanthanide, alkali, alkaline earth, and actinide metals have been combined with various organic linkers [15][16][17][18][19][20][21][22][23]. Therefore, currently it would be much more important to develop multifunctional MOFs that can present interesting functional behaviors such as luminescent, magnetic, ferroelectric, and photo/acoustically induced nonlinear optical properties as well as superb structures with conventional characteristics described above [24][25][26][27][28][29][30][31]. Until now, synthetic chemists have been introducing a series of trivalent p-elements to the new MOFs in order to mimic the open structures of zeo-type materials [32][33][34][35][36][37][38][39].…”

Recent advances in linear and non‐linear Raman spectroscopy. Part III

“…Using four-photon coherent spectroscopy, Bunkin and Pershin [82] have been able to observe for the first time the induced coherent rotations of H 2 O, D 2 O and HDO molecules coupled to their selective rotational transitions in bulk liquid. A possible strategy to obtain photo-induced optical second harmonic generation in an initially centrosymmetric single crystal (tristhioureacopper(I) perchlorate) has been established by Krishnakumar et al [83] Yamaguchi and Tahara [84] reported on coherent phonon detection in a thin gold film by a new femtosecond pump-probe surface plasmon resonance technique. Acoustic coherent phonons are generated impulsively in the gold film on a prism.…”