Open-shell spherical aromaticity: the 2N2 + 2N + 1 (with S = N + ½) rule

4N Baird's rule represented the extension of Hückel's 4N + 2 rule to triplet state systems. In this work we extend the 2(N + 1)(2) Hirsch rule for spherical aromatic species to open-shell spherical compounds and we provide evidence that those spherical species having a same-spin half-filled last energy level with the rest of the levels being fully-filled, i.e., those having 2N(2) + 2N + 1 electrons and S = N + ?, are aromatic.     

STUDY ON SYNTHESIS OF Mo_2N AND W_2N BY TPN

ＳＴＵＤＹ　ＯＮ　ＳＹＮＴＨＥＳＩＳ　ＯＦ　Ｍｏ_２Ｎ　ＡＮＤ　Ｗ_２Ｎ　ＢＹ　ＴＰＮＳＴＵＤＹＯＮＳＹＮＴＨＥＳＩＳＯＦＭｏ_２ＮＡＮＤＷ_２ＮＢＹＴＰＮ￥Ｗａｎｇ，Ｘｉｎ－ｐｉｎｇ；Ｗｅｉ，Ｚｈａｏ－ｂｉｎ；Ｒｅｎ，Ｔｉｅ－ｌｉａｎｄＸｉｎ，Ｑｉｎ（...     

Mononuclear palladacycles of N,N′-diaryl-2-iminoisoindolines

Reaction of acetato-bridged dinuclear palladacycles, [Pd(iminoisoindoline)(μ-OAc)]₂, with stoichiometric amounts of PR₃ (where R = Ph or Cy) resulted in formation of the corresponding mononuclear phosphine-ligated, six-membered palladacycles with the general formula [Pd(iminoisoindoline)(OAc)PR₃]. The analogous chloride complexes were synthesized by reaction of [Pd(iminoisoindoline)(μ-OAc)]₂ with LiCl in acetone followed by addition of phosphine to afford the monomeric derivatives [Pd(iminoisoindoline)(Cl)PR₃]. Representative crystal structures of both types of mononuclear palladacycles confirmed the mononuclear nature of the complexes and showed a trans-arrangement of the phosphine ligand to the heterocyclic imine-nitrogen of the palladacycles.     

N2(OH)2光致异构化机理

偶氮化合物 ,如偶氮芳烃、偶氮冠醚、偶氮环糊精等作为有机光化学开关分子具有重要的应用价值 ,已引起了人们的广泛重视[1] 。这类分子作为光化学开关的基本原理是反式的偶氮化合物在光照射下异构化为顺式构型 ,如下图所示 :长期以来 ,人们对该反应的机理持有两种不同看法[2 ,3] :一是分子平面内按角旋转机制 ,二是绕Ｎ =Ｎ键旋转的二面角机制。前者受氮上孤对电子的“阻碍” ,而后者将破坏共轭双键 ,显然两种机制在基态都很难发生 ,而如果光激发后发生ｎ→π 或π→π 跃迁 ,则两种机制均有可能发生。本文用量子化学从头算方法研究基态和激…     

cis-Bis[N1,N2-bis(trimethylsilyl)benz­amidinato-κ2N1,N2]chloro(4-tolyl­imido-κN)vanadium(V)

The title complex, [V(C₇H₇N)(C₁₃H₂₃N₂Si₂)₂Cl], consists of a V metal centre coordinated to five N atoms and a Cl⁻ ion in a pseudo-octahedral arrangement. The N atoms of the benzamidinate ligands form two four-membered chelate rings to V, with bite angles of 63.59 (8) and 64.36 (8)°, whilst the fifth N atom is from a p-tolyl­imido ligand [V—N—C 172.2 (2)°] located cis with respect to the Cl⁻ ion [Cl—V—N_imido 96.96 (8)°].     

New N2O2‐ and N2O3‐Macrocycle Ligands Incorporating p‐Xylyl Groups

Abstract

The synthesis and characterization of four dibenzo‐substituted macrocycles incorporating mixed nitrogen and oxygen heteroatoms as well as one or two xylyl groups are reported. The X‐ray structure of one product containing two xylyl functions is presented.     

N,N‘—二（2—羟基苄烯）—2—羟基苯甲基二胺及N,N’—二（2—羟基…

在四氢呋喃中合成了Ｓｃｈｉｆｆ碱配体Ｎ，Ｎ＇－二（２－羟基苄烯）－２－羟基苯甲基二胺（ＳＢ）与二阶过渡金属镍、铜、锌的三核或双核配合物；用钠汞齐还原ＳＢ得到了其氢化物Ｎ，Ｎ＇－二（２－羟基苄基）－２－羟基苯甲基二胺（ＨＳＢ），并在乙醇中合成了经与铜的双核配合物。对这些配合物进行了元素分析和热分析，并测定了电导、红外光谱和紫外光谱，确定了分子式，讨论了可能的配位结构。     

Lanthanide Complexes with N,N′-Bis(2- hydroxybenzylidene)-2-hydroxyphenylmethanediamine

Complexes of lanthanides with N,N-bis(2-hydroxybenzylidene)-2-hydroxyphenylmethanediamine (H₃L) were synthesized and investigated by the elemental, IR, magnetochemical, and thermogravimetric methods. Using the data obtained, they were found to have compositions Ln₂L₂ · nH₂O and La₂L₂ · MCl₂ · 4H₂O (Ln = La³⁺, Pr³⁺, Nd³⁺, Dy³⁺, Er³⁺; M = Cu²⁺, Co²⁺, Ni²⁺; n = 4, 6). Suggestions on their structures were made. In the interval of 20–140°C, these complexes were shown to be high-resistance semiconductors.     

CH_2=N=N→N=N■反应的过渡态及其反应途径的理论研究

本文讨论了用能量梯度法,在用MINDO/3自洽场方法计算得到的位能面上,分別优化得到线型和三员环型重氮甲烷以及这个单分子反应的过渡态的几何构型。研究了体系在过渡态的九种振动模式和反应途径。体系在反应途径上的每一点都保持C_S点群的对称性。轨道相关图表明反应是对称性允许的。     

C2v对称性簇Ru2N2的理论计算

采用密度泛函(B3LYP)方法计算了Ru2的部分低能电子组态，得到Ru2基态的电子谱项为7Δu，平衡核间距re=0.228 nm，振动频率ωe=338 cm－1，离解能De=1.92 eV. 同时计算了具有C2v对称性的Ru2N2簇中氮的活化情况，得到了各个优化几何构型下的键参数和体系能量.计算结果表明，氮氮键的活化程度由Ru2对氮起反馈作用的轨道数目决定.一般来说，氮氮键活化越强，体系能量越高，在相同的活化程度下，自旋多重度高的体系较稳定.     

N2O2的立体结构和键型

一氧化氮是奇电子分子,有聚合倾向。N_2O_2是NO在低温下生成的较弱的二聚物,其几何构型可能有以下三种形式(见图1);由于氮原子上孤对电子的排斥作用,分子不能自由绕N—N轴进行内旋转,因此可能有非环的顺式(C_(2v))和反式(C_(2(?)))构象;又由于NO是极性分子,偶极之间相互作用使得矩形(C_(2(?)))结构也是可能的,但根据振动光谱数据知,最稳定的是非环     

Über N1-Alkylsulfonyl-N2-butylharnstoffe

Zusammenfassung Es wird die Darstellung verschiedener N₁-Alkylsulfonyl-N₂-butylharnstoffe beschrieben. Diese Substanzen besitzen keine bakteriostatische Wirkung, sind aber ebenso wie die verschiedenen in der Literatur beschriebenen N₁-Arylsulfonyl-N₂-butylharnstoffe blutzuckersenkend.     

Synthesis and Crystal Structure of a N,N,N＇-tri（2-hydroxy-5-methylbenzyl）-l,2-ethanediamine

An aminophenol ligand, N,N,N＇-tri（2-hydroxy-5-methylbenzyl）-l,2-ethanediamine, was prepared through the Marmich reaction, and structurally characterized by NMR, IR, MS and single-crystal X-ray diffract...     

The CO2 stimulus-responsive spherical-worm-like micelles transition based on anionic surfactant sodium oleate and N,N, N′, N′, N″-pentamethyldipropylenetriamine

Here, we report a CO₂ stimulus-responsive system with anionic surfactant sodium oleate (NaOA) and N, N, N′, N′, N″-Pentamethyldipropylenetriamine (PMDPTA). The microstructure transition from spherical micelles to worm-like micelles was confirmed by rheology measurements, dynamic light scattering (DLS), and cryogenic transmission electron microscopy (Cyro-TEM). There were three types of CO_2?responsive groups in PMDPTA. However, because of PMDPTA ionization degrees, just one responsive group of PMDPTA could be ionized by CO₂ to work with OA^?, resulting in structure transformation from spherical micelles to worm-like micelles. Besides, this system could be switchable between low-viscosity fluid and high viscoelastic by CO₂/N₂.     

One-pot synthesis of C2-symmetric N,N′-diaryl bis(oxazolidin-2-ones) as precursors for N,N′-diaryl 2,3-diamino-1,4-butanediols

A new and general one-pot synthetic method for C₂-symmetric N,N′-aryl-disubstituted bis(oxazolidin-2-ones) has been developed. Highly regioselective intramolecular cyclization reactions of 2,3-di(methanesulfonyloxy)-1,4-dihydroxybutane with arylisocyanates in the presence of sodium hydride afforded the corresponding C₂-symmetric N,N′-aryl-disubstituted bis(oxazolidin-2-ones) in 82–92% yields. Hydrolytic ring opening of the bis(oxazolidin-2-ones) provided a convenient synthetic route for optically pure C₂-symmetric N,N′-aryl-disubstituted 2,3-diamino-1,4-butanediols (58–86% yields).     

Complexation of the N,N′,O-donor ligand N-trans-(2′-hydroxycyclohexyl)-2-aminomethylpyridine

The potentially tridentate N,N′,O-donor N-trans-(2′-hydroxycyclohexyl)-2-aminomethylpyridine (1) forms ML₂ complexes with M(II)?=?Cu, Ni, and Zn. X-ray crystal structures of the isostructural Ni(II) and Zn(II) complexes confirm bis-tridentate coordination in significantly distorted octahedral geometries as the all-cis facial isomer. Structural comparisons with the previously reported all-trans facial Cu(II) and cis,cis,trans(N_py) facial Co(III) complexes are presented. Protonation constants for 1 and stability constants with Cu(II), Ni(II), and Zn(II) are reported, with both ML and ML₂ species defined. The trend for ML (log K ₁ values for Cu, Ni, and Zn of 8.3, 6.9, and 5.3, respectively) is conventional. Protonation and stability constants with Cu(II) for N,N-bis(2-pyridylmethyl)amine (2) were also defined. The log K ₁ value measured for 2 of 7.4 is very similar to that found for 1 of 8.3, despite the marked difference in the third donor group; it appears that the third donor of the tridentate ligand generally binds only poorly to Jahn–Teller elongated Cu(II) in solution.     

气相中H2O2与N2O反应机理的探讨

采用RHF/AM1方法研究了H2O2与N2O的反应机理.计算结果表明,该反应是多步反应,先后通过2个过渡态（TS1,TS3）,1个内旋转位垒（TS2）,2个中间体（IM1,IM2）.其中从反应物Re到TS1为整个反应的决速步骤,速控步骤的活化能为323.04 kJ•mol－1.整个反应为一放热反应,放出的热量为147.67kJ•mol－1.