Nucleophilic Substitution Reactions of 2,4,6-Tris(trinitromethyl)-1,3,5-triazine. 3. Reaction of 2,4,6-Tris(trinitromethyl)-1,3,5-triazine with Azides and Hydrazine

As a result of nucleophilic substitution of the trinitromethyl groups in 2,4,6-tris(trinitromethyl)-1,3,5-triazine, the corresponding monoazido and diazido derivatives have been synthesized. The reaction of the starting triazine with hydrazine acetate in the presence of trifluoroacetic acid leads to 1-acetyl-2,2-bis[4,6-bis(trinitromethyl)-1,3,5-triazin-2-yl]hydrazine.     

Trisubstituted 1,3,5-Triazines. 6. Synthesis of 2,4,6-Tris(acetonyl)-1,3,5-triazine

Acylation of 2,4,6-tris(tert-butoxycarbonylmethyl)-1,3,5-triazine with acetic anhydride in the presence of lithium hydride with subsequent removal of the tert-butoxycarbonyl groups with trifluoroacetic acid leads to 2,4,6-tris(acetonyl)-1,3,5-triazine, the cyclic analog of -cyanoacetone. The special spectral features of this compound compared with triazines obtained previously are discussed.     

2,4,6-三对氨基苯氧基-1,3,5-均三嗪的合成

以三聚氯氰和对硝基苯酚为原料,经取代、还原合成了2,4,6-三对氨基苯氧基-1,3,5-均三嗪。对Pd/C水合肼、SnCl2·2H2O-HCl及Pd/C催化加氢三种不同还原体系进行比较。采用1H-NMR、FT-IR和元素分析方法对产物进行结构表征。     

金属调控的2，4，6-三(2-吡啶基)-1，3，5-三嗪基配合物的光致变色性能

在溶剂热条件下,将2,4,6?三(2?吡啶基)?1,3,5?三嗪(2?TPT)、2,5?呋喃二羧酸(2,5?H₂FCA)分别与不同类型的金属硝酸盐(Zn、Cd和Mn)进行组装,得到了3个2?TPT基配合物:[Zn(2?TPT)(2,5?FCA)](1)、[Cd(2?TPT)(2,5?FCA)]·1.5H₂O(2)和[Mn(2?TPT)(2,5?FCA)](3)。通过单晶X射线衍射、粉末X射线衍射、FT?IR、UV?Vis、差热-热重、电子顺磁共振和X射线光电子能谱对1~3的结构和光致变色性能进行了表征,并详细地探究了其光致变色机理。配合物1~3表现出明显差异的光诱导分子间电子转移和光致变色性能,主要体现在光响应速率和颜色对比度2个方面。其中,1的光致变色性能明显优于2,而3不具有光致变色行为。这种明显差异的光致变色行为,主要归因于不同类型的金属及其配位模式的差异所引起的不同晶体堆积模式和电子给体-受体间相对位置关系(界面关系),体现出了金属对于光致变色性能的调控作用。     

2,4,6-Tri(4-pyridyl)-1,3,5-triazine: Photoinduced Charge Separation and Photochromism in the Crystalline State

2,4,6-Tri(4-pyridyl)-1,3,5-triazine (tpt) is a widely used ligand for functional coordination compounds. In this work, tpt has shown unprecedented photochromism in the crystalline state. Experimental and theoretical data has revealed that the photocoloration of tpt very likely originates from intramolecular charge separation and the formation of a triplet diradical product. This finding demonstrates a new simple, neutral photochromic molecule and endows the tpt molecule and related compounds with potential optical applications.     

Syntheses and crystal structures of copper(II) complexes derived from 2,4,6-tris(2-pyridyl)-1,3,5-triazine

Treatment of freshly precipitated Cu(OH)₂?·?xH₂O and 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz) with oxalic and malonic acids in methanol-water at room temperature gave [Cu(tptz)(C₂O₄)(H₂O)]?·?4H₂O (1) and [Cu(pma)(C₃H₂O₄)(H₂O)]?·?H₂O (2) (pma?=?2-aminocarbonylpyridine), respectively. Reaction in the absence of any acid resulted in [Cu(bpca)(tca)]?·?2H₂O (3) (bpca?=?bis(2-pyridylcarbonyl)amide anion; tca?=?2-pyridinecarboxylate anion). Complex 1 consists of [Cu(tptz)(C₂O₄)(H₂O)] and lattice H₂O molecules; the tridentate tptz ligand, bidentate oxalate dianion and an aqua ligand are bound to Cu with distorted octahedral geometry. Complex 2 is composed of [Cu(pma)(C₃H₂O₄)(H₂O)] and lattice H₂O molecules; the bidentate 2-aminocarbonylpyridine ligand, a bidentate malonate dianion and an aqua ligand are coordinated to Cu with a slightly distorted square pyramidal geometry. Complex 3 consists of [Cu(bpca)(tca)] and lattice H₂O molecules. Square pyramidally coordinated Cu atoms are surrounded by tridentate bpca with nitrogen donor atoms and a bidentate 2-pyridinecarboxylate anion.     

Luminescent nine-coordinate lanthanide complexes derived from fluorinated β-diketone and 2,4,6-tris(2-pyridyl)-1,3,5-triazine

The synthesis, photoluminescence, 4f–4f absorptions, and NMR studies of nine-coordinate lanthanide(III) complexes, [Ln(tfaa)₃(tptz)] (Ln?=?La, Nd, Sm, and Eu; tfaa is the anion of 1,1,1-trifluoro-2,4-pantanedione; and tptz?=?2,4,6-tris(2-pyridyl)-1,3,5-triazine), are reported. These complexes are synthesized in a single pot by in situ method and thoroughly characterized. The β-diketone and tptz chemical shifts, in the cases of paramagnetic complexes, are in the opposite directions. The lanthanide-induced shifts are dipolar in nature. The luminescence and 4f–4f absorptions are analyzed and discussed. The samarium and europium complexes emit strong pink and red luminescences due to ⁴G_5/2?→?⁶H_j (j?=?5/2, 7/2, 9/2) and ⁵D₀?→?⁷F_j (j?=?0–4) transitions, respectively. The ⁴G_5/2→⁶H_7/2 (607?nm) emission transition of Sm(III) has no Stark components and indicates a higher local symmetry around Sm(III). The very strong hypersensitive ⁵D₀?→?⁷F₂ transition of Eu reflects a highly polarizable chemical environment around Eu(III). The absorption spectra of the neodymium complex are investigated and analyzed.     

2,4,6-Tris(4-nitrophenoxy)-1,3,5-triazine: a hexagonal host framework stabilised by the NO2-trimer supramolecular synthon

The title molecule forms a honeycomb network of molecular and nitro-trimer synthons with guest species included in the hexagonal voids.     

Trisubstituted 1,3,5-Triazines. 5. Reaction of 2,4,6-Tris[di(tert-butoxycarbonyl)nitromethyl]-1,3,5-triazine with Nucleophiles

The reaction of 2,4,6-tris[di(tert-butoxycarbonyl)nitromethyl]-1,3,5-triazine with ammonia, amines, and hydrazine has been studied. It was possible to substitute one of the di(tert-butoxycarbonyl)nitromethyl groups in this compound in the presence of ammonia, primary aliphatic amines, dimethylamine, and morpholine. The reaction with hydrazine leads to both mono- and disubstituted products. A double dealkoxylation occurs in the presence of diethylamine to give the bis(dimethylammonium) salt of 2,4-bis(tert-butoxycarbonylnitromethyl)-6-[di(tert-butoxycarbonyl)nitromethyl]-1,3,5-triazine.     

Crystal Structures and Packing of 2,4,6-tris(4-Fluorophenoxy)-1,3,5-triazine and 2,4,6-tris(3,4-Dimethylphenoxy)-1,3,5-triazine. New Materials for Octupolar Nonlinear Optics

The crystal structures and packing of 2,4,6-tris(4-fluorophenoxy)-1,3,5-triazine and 2,4,6-tris(3,4-dimethylphenoxy)-1,3,5-triazine are discussed. These structures have been determined as a continuation of a series of octupolar NLO materials we have been investigating. The crystal structures are characterized by C–H...F and C–H... hydrogen bonds, respectively. A characteristic of these triazine structures is the presence of dimeric Piedfort Units (PU) that are extended into more elaborate two-dimensional (2-D) networks. The structure of the fluoro derivative is compared with that of the corresponding unsubstituted and chloro/bromo-substituted derivatives. The structure of the dimethyl triazine is compared with that of the corresponding 4-methyl derivative. The noncentrosymmetric nature of the dimethyl derivative was confirmed by a powder SHG signal at 1.064 m of the order of 0.5 × KDP. Interestingly, the dimethyl derivative studied here is isostructural with the corresponding 4-methyl triazine. This H/Me isostructurality is shown to be an uncommon phenomenon by an analysis with the CSD.     

Coordination chemistry of 2,4,6-tri(pyridyl)-1,3,5-triazine ligands

This review covers the rich coordination chemistry of 2,4,6-tri(pyridyl)-1,3,5-triazine ligands. These polypyridyl derivatives have been coupled to transition metals and lanthanides, and the complexes obtained have been used in various fields such as luminescent materials, for the preparation of coordination polymers and networks as well as for the synthesis of discrete metalla-assemblies. The synthetic and structural aspects of the different isomers of 2,4,6-tri(pyridyl)-1,3,5-triazine are presented, and a survey of their coordination chemistry is given.     

Group 13 Metal Halide Based Coordination Polymers of Al,Ga, In and 2,4,6-Tri(4-pyridyl)-1,3,5-triazine

Four isotypic one-dimensional coordination polymers (CP) were synthesized using the group 13 metal halides AlBr₃, GaCl₃, GaBr₃, and InI₃ and the tridentate ligand 2,4,6-tri(4-pyridyl)-1,3,5-triazine (tpt) serving as bidentate linker. The neutral one-dimensional CPs ¹_∞[AlBr₃(tpt)], ¹_∞[GaCl₃(tpt)], ¹_∞[GaBr₃(tpt)], and ¹_∞[InI₃(tpt)] are constituted by zigzag-shaped chains in the crystal structure, in which one coordination site of the tpt ligand remains uncoordinated. All CPs were characterized by SCXRD, PXRD, simultaneous DTA/TG, elemental-analysis and IR spectroscopy. Furthermore, three complexes of the composition [(AlBr₃)₃(tpt)], [(GaCl₃)₃(tpt)], and [(GaBr₃)₃(tpt)] were structurally characterized by SCXRD, being preliminary and side products of the formation of the coordination polymers.