Nitro-Nitrito Photoisomerization of Cationic Platinum(II) Complexes in the Solid State: Reactivity in Polymorphic Crystals and Glassy State
Nitro-Nitrito Photoisomerization of Cationic Platinum(II) Complexes in the Solid State: Reactivity in Polymorphic Crystals and Glassy State
复制标题
固态阳离子铂(II)配合物的硝基-亚硝基光异构化：多晶态和玻璃态的反应性
DOI：
10.1021/acs.cgd.1c00004
复制
发表时间：
2021
影响因子：
3.8
通讯作者：
Mochida Tomoyuki
中科院分区：
文献类型：
--
作者：
Nakamura Ibuki;Sumitani Ryo;Mochida Tomoyuki
亚硝基-亚硝基异构化是金属配合物在固体状态下发生的一种众所周知的光化学反应。我们之前报道了阳离子铂（II）亚硝基配合物[Pt(L)(NO2)]+（L =N1-（2-（二甲氨基）乙基）- n2， n2 -二甲基-N1-戊基-1,2-乙二胺）盐的异构化率与亚硝基配体周围的反应腔有关。在本研究中，为了进一步阐明包装结构对反应的影响，我们研究了同一阳离子在不同包装环境下的光异构化。阳离子盐与pf6阴离子的配合物形成三种多晶型（α-型、β-型和γ-型）和一种伪多晶型（δ-型，乙腈溶剂化物），其中γ-型是乙腈脱附后δ-型形成的。根据反应腔的不同，这些多晶在180 K下的转化率为36-100%。此外，β-形态在光照射下发生空间基团变化。含（CF3SO2） 2n阴离子的盐为离子液体，在低温下呈结晶态和玻璃态。在100 K下，晶体状态表现出约30%的转化率，而红外光谱研究表明，在玻璃态下没有观察到光异构化。在这些盐中，不太密集的晶体在光照射下变质。
Nitro–nitrito isomerization is a well-known photoreaction exhibited by metal complexes in the solid state. We previously reported that the isomerization ratio in the salts of a cationic platinum(II) nitrito complex [Pt(L)(NO2)]+(L =N1-(2-(dimethylamino)ethyl)-N2,N2-dimethyl-N1-pentyl-1,2-ethanediamine) is correlated to the reaction cavity surrounding the nitrito ligand. In this study, to further elucidate the effect of the packing structure on the reaction, we investigated the photoisomerization of the same cation in different packing environments. The salt of the cationic complex with the PF6anion gave three polymorphs (α-, β-, and γ-forms) and a pseudopolymorph (δ-form, acetonitrile solvate), of which the γ-form is formed from the δ-form upon desorption of acetonitrile. These polymorphs exhibited 36–100% conversions at 180 K depending on the reaction cavity. In addition, the β-form exhibited a space group change upon photoirradiation. The salt with the (CF3SO2)2N–anion was an ionic liquid, taking both the crystalline and glassy states at low temperature. The crystalline state exhibited approximately 30% conversion at 100 K, whereas photoisomerization was not observed in its glassy state as investigated by IR spectroscopy. In these salts, less densely packed crystals deteriorated upon photoirradiation.