Example of Disulfide Conformational Change in the Solid State: Preparation, Optical Properties, and X‐ray Studies of a Cystamine‐Based Iodoplombate Hybrid

Abstract

A novel cystamine-based hybrid, namely, α-[{NH 3 (CH 2 ) 2 SS-(CH 2 ) 2 NH 3 }PbI 6 ]·2H 3 O (1a), was prepared under solvothermal conditions. Interestingly, 1a, which is built up from isolated PbI 6 octahedra, can be easily changed into its polymorph, namely, β-[{NH 3 (CH 2 ) 2 S-S(CH 2 ) 2 NH 3 }PbI 6 ]·2H 3 O (1b) only by heating it up to 45°C. According to the results of X-ray diffraction analyses, the polymorphic phenomenon of 1a and 1b results from a conformational change in the heli-

Ferroelectric AgNa(NO2)2 crystals as novel highly efficient nonlinear optical material: Phase matched second harmonic generation driven by a spontaneous and electric field induced polarizations

“…Obtained results are interpreted within the phenomenological theory which considers the free energy describing the interaction between the spontaneous or electric field induced polarizations and spatially inhomogeneous electric polarizations resulted from propagating optical waves. At 30,31 However, it is more important that relatively high magnitudes of the effective NLO susceptibilities are combined in AgNa͑NO 2 ͒ 2 crystals with several PMGs. This allows to consider them as high-performance materials for potential NLO applications, such as frequency doubling, parametric generation and amplification, or other applications that require a high-efficient frequency conversion.…”

Structural diversity and retro-crystal engineering analysis of iodometalate hybrids

“…On the contrary, molecules with a terminal cationic group with H-bonding donors, typically primary ammonium, will favour monodentate iodides in the less condensed networks with a high I/M ratio, as in the case of 2D hybrid perovskites or 1D derivative networks, (Fig. 3: Pb 5 I 22 (I/M ¼ 4.4), 28 Pb 3 I 14 (I/M ¼ 4.66), 28 Pb 2 I 10 (]PbI 5 , I/M ¼ 5) 27 and PbI 6 (I/M ¼ 6) 26 ). An important factor in the formation of iodometalate hybrid crystals are certainly the interactions between cationic and subunit anionic entities which exist in solution before crystallization.…”

Noncovalent Chalcogen Bonds and Disulfide Conformational Change in the Cystamine‐Based Hybrid Perovskite [H3N(CH2)2SS(CH2)2NH3]PbIII4

“…[43][44][45] We supposed that treating PbI 2 with H 2 cys and HI in a mixture of acetonitrile and a polar protic solvent should give interesting results owing to the fact that the created ionic species such as H 3 O + should be more strongly attracted by the protic solvent (i.e., solvated) than by the sulfur atoms of the disulfide group of H 2 cys dications. In the "H 2 cys series", it is interesting to note that all compounds have been crystallised using acetonitrile as a solvent, and all compounds, from n = 1 to n = 5, incorporate guest molecules (H 3 O + , H 2 O or even I 2 ).…”

“…Up to now, the "H 2 cys series" was composed of (H 2 cys) 2 PbI 6 ·2H 3 O (n = 1, being composed of isolated PbI 6 octahedra), [43] (H 2 cys) 2 Pb 2 I 10 ·2H 3 O [n = 2, the formula being reduced to (H 2 cys)PbI 5 ·H 3 O], [44] (H 2 cys) 4 Pb 3 I 14 ·I 2 (n = 3) and (H 2 cys) 6 Pb 5 I 22 ·4H 2 O (n = 5). [45] All inorganic anions for each member of the series can be regarded as a dimensional reduction of 2D hybrid perovskite layers, thus the dual nature of the H 2 cys cation is highlighted: on the one hand, it is able to stabilise networks of corner-sharing PbI 6 octahedra as is expected for nonbulky primary ammonium cations, and on the other hand, it might prevent the formation of hybrid perovskite layers owing to the strong capability of trapping guest molecules by means of noncovalent interactions between the disulfide bridge and its neighbouring environment.…”