2 research outputs found
Zeolite-like Topology Oxonitridosilicate La<sub>3.6</sub>Ba<sub>1.7</sub>Si<sub>5</sub>N<sub>10</sub>O<sub>2.1</sub> with Potential Applications in Nonlinear Optical Materials
A novel zeolite-like topology oxonitridosilicate La3.6Ba1.7Si5N10O2.1 with
the space group Amm2 (no. 38) and lattice parameters a = 9.5193 (3) Å, b = 16.7011 (5)
Å, c = 26.0279 (8) Å, and Z = 12 has been synthesized by a high-temperature solid-state reaction.
The crystal structure of La3.6Ba1.7Si5N10O2.1 has four different kinds of tiling,
and the cages in the structure are filled with La, Ba, and O atoms.
The presence of a noncentrosymmetric space group further suggests
its potential for nonlinear optical (NLO) applications, and La3.6Ba1.7Si5N10O2.1 demonstrated a stronger second-harmonic generation (SHG) response
than that of SiO2
Crystal Growth, Intermolecular Noncovalent Interactions, and Photoluminescence Properties of Halogenated Phthalic Anhydride-Based Organic Charge Transfer Cocrystals
Organic
charge-transfer cocrystals are composed of an electron-rich
donor molecule and an electron-deficient acceptor molecule, which
are bonded together by intermolecular noncovalent interactions such
as π–π interactions, hydrogen bonds, halogen bonds,
and charge-transfer interactions. These noncovalent interactions influence
the cocrystal packing structures and the photoluminescence properties.
Herein, four charge transfer cocrystals, pyrene-tetrafluorophthalic
anhydride (TFPA), perylene-TFPA, pyrene-tetrachlorophthalic anhydride
(TCPA), and perylene-TCPA, were grown by the slow cooling method and
the influence of intermolecular noncovalent interactions on the photoluminescence
properties were investigated. Cocrystals of pyrene-TFPA and pyrene-TCPA
exhibit a yellow rod-like morphology, while both perylene-TFPA and
perylene-TCPA exhibit red rod-like shapes. Results indicate that the
C–H···X (X = F, Cl, or O) interactions, π–π
interactions, and charge-transfer interactions are dramatically affected
by the energy difference between the HOMO of the donor and the LUMO
of the acceptor. Meanwhile, for the same acceptor molecules, the positions
of the photoluminescence peaks of the cocrystals red-shifted with
the enhancement of weak noncovalent interactions, which paved the
way to tuning the optical properties of charge transfer cocrystals