Domasevitch Kostiantyn V, Senchyk Ganna A, Krautscheid Harald
Inorganic Chemistry Department, National Taras Shevchenko University of Kyiv, Volodymyrska Str. 64/13, 01601 Kyiv, Ukraine.
Institute of Inorganic Chemistry, Leipzig University, Johannisallee 29, D-04103 Leipzig, Germany.
Acta Crystallogr E Crystallogr Commun. 2023 Jun 20;79(Pt 7):657-663. doi: 10.1107/S2056989023005339. eCollection 2023 Jun 1.
In the structure of the title salt, [Li(CNO)(HO)], the 3,3',5,5'-tetra-nitro-4,4'-bi-pyrazole-1,1'-diide dianion [{TNBPz}] is situated across the twofold axis. The distorted coordination octa-hedra around Li involve four short bonds with two pyrazolate N atoms and two aqua ligands [Li-N(O) = 1.999 (3)-2.090 (2) Å] and two longer contacts with nitro-O atoms [2.550 (2), 2.636 (2) Å]. When combined with μ-{TNBPz}, this generates a mono-periodic polymeric structure incorporating discrete centrosymmeric [(HO)Li-(di-nitro-pyrazolato)-Li(HO)] units. The three-dimensional stack of mutually orthogonal coordination chains is reminiscent of a Lincoln log pattern. It is influenced by conventional hydrogen bonding [O⋯O = 2.8555 (17)-3.0010 (15) Å] and multiple lone pair-π hole inter-actions of the nitro groups [N⋯O = 3.0349 (15) and 3.0887 (15) Å]. The Hirshfeld surface and two-dimensional fingerprint plots also support the significance of non-covalent bonding. Coordinative saturation and a favorable geometry at the Li ions, dense packing of the polymeric subconnectivities and particularly extensive inter-anion inter-actions may be involved in the stabilization of the structure. The title salt is a rare example of an energetic Li nitro-azolate, which nicely crystallizes from aqueous solution and is neither hygroscopic nor efflorescent. The TG/DTA data reveal total dehydration in the range of 330-430 K and stability of the anhydrous material up to 633-653 K.
在标题盐[Li(CNO)(H₂O)]的结构中，3,3',5,5'-四硝基-4,4'-联吡唑-1,1'-二负离子[{TNBPz}]位于二重轴上。Li周围扭曲的配位八面体涉及与两个吡唑啉氮原子和两个水配体形成的四个短键[Li-N(O)=1.999(3)-2.090(2)Å]以及与硝基氧原子形成的两个较长键[2.550(2),2.636(2)Å]。当与μ-{TNBPz}结合时，这产生了一种单周期聚合物结构，其中包含离散的中心对称[(H₂O)Li-(二硝基吡唑啉基)-Li(H₂O)]单元。相互正交的配位链的三维堆积让人联想到积木结构。它受到传统氢键[O⋯O = 2.8555(17)-3.0010(15)Å]和硝基的多个孤对-π空穴相互作用[N⋯O = 3.0349(15)和3.0887(15)Å]的影响。Hirshfeld表面和二维指纹图谱也支持非共价键的重要性。Li离子处的配位饱和以及有利的几何形状、聚合物亚连接性的紧密堆积，特别是广泛的阴离子间相互作用可能参与了结构的稳定。该标题盐是一种罕见的高能锂硝唑酸盐实例，它能很好地从水溶液中结晶出来，既不吸湿也不风化。TG/DTA数据表明在330 - 430K范围内完全脱水，无水材料在高达633 - 653K时稳定。
