Polymorph Control of Luminescence Properties in Molecular Crystals of a Platinum and Organoarsenic Complex and Formation of Stable One-Dimensional Nanochannel

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• 作者：Hikaru Unesaki ; Takuji Kato ; Seiji Watase ; Kimihiro Matsukawa ; Kensuke Naka
• 刊名：Inorganic Chemistry
• 出版年：2014
• 出版时间：August 18, 2014
• 年：2014
• 卷：53
• 期：16
• 页码：8270-8277
• 全文大小：465K
• ISSN：1520-510X

文摘

The mononuclear diiodoplatinum(II) complex (trans-PtI₂(cis-DHDAMe)₂), where cis-DHDAMe = cis-1,4-dihydro-1,4-dimethyl-2,3,5,6-tetrakis(methoxycarbonyl)-1,4-diarsinine, forms three different crystalline polymorphs that can be either concomitantly or separately obtained on varying the recrystallization conditions. Cubic red crystals (伪-phase) and red-orange needles (尾-phase) exhibit solid-state red emissions at room temperature. Cubic red crystals of the 纬-phase show no solid-state emission at room temperature. All crystalline structures were confirmed by X-ray crystallography. Room-temperature strongly luminescent crystals (伪-phase) (位_em = 657 nm, 桅 = 0.52) have a triclinic P1̅ (No. 2) structure and no voids in the crystal structure. Red-orange needle-shaped crystals of the 尾-phase exhibit moderate red luminescence (位_em = 695 nm, 桅 = 0.09) at room temperature and have a trigonal, R3̅ (No. 148), structure. In the needlelike crystals of the 尾-phase, stable hexagonal arrays of nanoporous channels, 5.0 脜 in diameter, are formed. Room-temperature nonluminescent crystals (纬-phase) have an orthorhombic, Pbca (No. 61), structure with a void volume that is 4.9% of the total crystal volume. After heating the 伪-phase crystals at 150 掳C for 2 min, a powder XRD pattern different from the original crystal is obtained, and its solid-state emission at room temperature decreased. After heating the 尾-phase crystals at 150 掳C for 2 min, the emission wavelength and the quantum yield of the solid-state emission at room temperature and the powder XRD pattern are the same as those of the 伪-phase after heating at 150 掳C. A crystal-to-crystal transition triggered by the thermal stimulus produces a different stable polymorph of the mononuclear diiodoplatinum(II) complex. The one-dimensional nanoporous crystals encapsulated iodine without distorting the crystal packing.