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61.
High‐Pressure Synthesis of a Nitrogen‐Rich Inclusion Compound ReN8⋅x N2 with Conjugated Polymeric Nitrogen Chains
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Dr. Maxim Bykov Dr. Elena Bykova Egor Koemets Timofey Fedotenko Georgios Aprilis Dr. Konstantin Glazyrin Dr. Hanns‐Peter Liermann Dr. Alena V. Ponomareva Johan Tidholm Dr. Ferenc Tasnádi Prof. Dr. Igor A. Abrikosov Prof. Dr. Natalia Dubrovinskaia Prof. Dr. Leonid Dubrovinsky 《Angewandte Chemie (International ed. in English)》2018,57(29):9048-9053
A nitrogen‐rich compound, ReN8?x N2, was synthesized by a direct reaction between rhenium and nitrogen at high pressure and high temperature in a laser‐heated diamond anvil cell. Single‐crystal X‐ray diffraction revealed that the crystal structure, which is based on the ReN8 framework, has rectangular‐shaped channels that accommodate nitrogen molecules. Thus, despite a very high synthesis pressure, exceeding 100 GPa, ReN8?x N2 is an inclusion compound. The amount of trapped nitrogen (x) depends on the synthesis conditions. The polydiazenediyl chains [?N=N?]∞ that constitute the framework have not been previously observed in any compound. Ab initio calculations on ReN8?x N2 provide strong support for the experimental results and conclusions. 相似文献
62.
Dr. Bartholomäus Pieber Dr. Menny Shalom Prof. Dr. Markus Antonietti Prof. Dr. Peter H. Seeberger Dr. Kerry Gilmore 《Angewandte Chemie (International ed. in English)》2018,57(31):9976-9979
Solid reagents, leaching catalysts, and heterogeneous photocatalysts are commonly employed in batch processes but are ill‐suited for continuous‐flow chemistry. Heterogeneous catalysts for thermal reactions are typically used in packed‐bed reactors, which cannot be penetrated by light and thus are not suitable for photocatalytic reactions involving solids. We demonstrate that serial micro‐batch reactors (SMBRs) allow for the continuous utilization of solid materials together with liquids and gases in flow. This technology was utilized to develop selective and efficient fluorination reactions using a modified graphitic carbon nitride heterogeneous catalyst instead of costly homogeneous metal polypyridyl complexes. The merger of this inexpensive, recyclable catalyst and the SMBR approach enables sustainable and scalable photocatalysis. 相似文献
63.
Cover Picture: Controlled Expansion of a Strong‐Field Iron Nitride Cluster: Multi‐Site Ligand Substitution as a Strategy for Activating Interstitial Nitride Nucleophilicity (Angew. Chem. Int. Ed. 40/2018)
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64.
Carsten L. Schmidt Ulrich Wedig Dr. Robert Dinnebier Prof. Dr. Martin Jansen Prof. Dr. 《化学:亚洲杂志》2008,3(11):1983-1990
The new barium nitridoosmate oxide (Ba6O)(OsN3)2 was prepared by reacting elemental barium and osmium (3:1) in nitrogen at 815–830 °C. The crystal structure of (Ba6O)(OsN3)2 as determined by laboratory powder X‐ray diffraction ( , No 148: a=b=8.112(1) Å, c=17.390(1) Å, V=991.0(1) Å3, Z=3), consists of sheets of trigonal OsN3 units and trigonal‐antiprismatic Ba6O groups, and is structurally related to the “313 nitrides” AE3MN3 (AE=Ca, Sr, Ba, M=V–Co, Ga). Density functional calculations, using a hybrid functional, likewise indicate the existence of oxygen in the Ba6 polyhedra. The oxidation state 4+ of osmium is confirmed, both by the calculations and by XPS measurements. The bonding properties of the OsN35? units are analyzed and compared to the Raman spectrum. The compound is paramagnetic from room temperature down to T=10 K. Between room temperature and 100 K it obeys the Curie–Weiss law (μ=1.68 μB). (Ba6O)(OsN3)2 is semiconducting with a good electronic conductivity at room temperature (8.74×10?2 Ω?1 cm?1). Below 142 K the temperature dependence of the conductivity resembles that of a variable‐range hopping mechanism. 相似文献
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66.
Bojdys MJ Müller JO Antonietti M Thomas A 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(27):8177-8182
Herein we report the synthesis of a crystalline graphitic carbon nitride, or g-C(3)N(4), obtained from the temperature-induced condensation of dicyandiamide (NH(2)C(=NH)NHCN) by using a salt melt of lithium chloride and potassium chloride as the solvent. The proposed crystal structure of this g-C(3)N(4) species is based on sheets of hexagonally arranged s-heptazine (C(6)N(7)) units that are held together by covalent bonds between C and N atoms which are stacked in a graphitic, staggered fashion, as corroborated by powder X-ray diffractometry and high-resolution transmission electron microscopy. 相似文献
67.
Marta Falcone Dr. Christos E. Kefalidis Rosario Scopelliti Prof. Laurent Maron Prof. Marinella Mazzanti 《Angewandte Chemie (International ed. in English)》2016,55(40):12290-12294
Uranium nitrides are important materials with potential for application as fuels for nuclear power generation, and as highly active catalysts. Molecular nitride compounds could provide important insight into the nature of the uranium–nitride bond, but currently little is known about their reactivity. In this study, we found that a complex containing a nitride bridging two uranium centers and a cesium cation readily cleaved the C≡O bond (one of the strongest bonds in nature) under ambient conditions. The product formed has a [CsU2(μ‐CN)(μ‐O)] core, thus indicating that the three cations cooperate to cleave CO. Moreover, the addition of MeOTf to the nitride complex led to an exceptional valence disproportionation of the CsUIV–N–UIV core to yield CsUIII(OTf) and [MeN=UV] fragments. The important role of multimetallic cooperativity in both reactions is illustrated by the computed reaction mechanisms. 相似文献
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