- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Rivalry Under Pressure - The Coexistence of Ambient-pressure Motifs and Close-packing in Silicon Phosphorus Nitride Imide SiP2N4NH
摘要： Non-metal nitrides such as BN, Si3N4 and P3N5 meet numerous demands on high-performance materials and their high-pressure polymorphs exhibit outstanding mechanical properties. Herein, we present the silicon phosphorus nitride imide SiP2N4NH featuring six-fold coordinated Si. Using the multianvil technique, SiP2N4NH was obtained from high-pressure high-temperature synthesis at 8 GPa and 1100 °C with in situ formed HCl acting as a mineralizer. Its structure was elucidated by combination of single-crystal X-ray diffraction and solid-state NMR measurements. Moreover, SiP2N4NH was characterized by energy-dispersive X-ray spectroscopy and (temperature-dependent) powder X-ray diffraction. The highly condensed Si/P/N framework features PN4 tetrahedra as well as the rare motif of SiN6 octahedra and is discussed in the context of ambient-pressure motifs competing with close-packing of nitride anions, representing a missing link in high-pressure chemistry of non-metal nitrides.
关键词： nitrides,silicon,high-pressure chemistry,phosphorus,solid-state structures
更新于2025-09-23 15:22:29
-
Silver-chalcogen frameworks: crystal and electronic structure of [Ag3S](NO3) and a comparison with [Ag4Te](SO4)
摘要： Crystal and electronic structure of silver-containing metal-inorganic frameworks [Ag3S](NO3) and [Ag4Te](SO4) have been examined. For [Ag3S](NO3), the crystal structure has been re-determined from X-ray single crystal diffraction data and refined to R = 2.7% in order to determine the exact position of the nitrate anion. It is shown that the main structural feature of [Ag3S](NO3) and [Ag4Te](SO4) is the framework based on the combination of silver-chalcogen and silver-silver interactions, with guest oxoanions filling the cavities. Effectively, ionic interactions between guest anions and the framework differ significantly from the interactions within frameworks themselves, where the bonding analysis shows the tendency for more covalent bonding and indicates that the bonding patterns are consistent with what is regarded as metallophilic interactions.
关键词： Frameworks compounds,Silver,Solid-state structures,Metallophilic interactions,Electronic structure
更新于2025-09-19 17:15:36
-
1,8,10-Substituted Anthracenes – Hexafunctional Frameworks via Head-to-Tail Photodimerisation
摘要： Several 1,8,10-functionalised anthracene derivatives and a couple of 1,8,9-functionalised anthracene analogous, bearing alkynyl substituents at positions 1 and 8 were synthesised and their photochemistry investigated in UV irradiation experiments. Almost all compounds could be converted into their 9,10:10′,9′-head-to-tail photodimers completely excluding the formation of the corresponding head-to-head isomers. Working under non-inert conditions led to formation of endoperoxides in some cases. Furthermore, a non-classical [4π+2π] photodimer was obtained from 1,8,10-tris[(trimethylsilyl)ethynyl]anthracene with one of the alkynyl substituents involved in the photoreaction. The 1H and 13C NMR spectra of all classical and non-classical photodimers were compared with those of the endoperoxides identifying characteristic shifts for the atoms at positions 9 and 10. Moreover, solid-state structures were determined for one or more of each representative.
关键词： photodimerisation,non-classical photodimers,solid-state structures,anthracenes,endoperoxides
更新于2025-09-04 15:30:14