N,N′,N′′,N′′′‐Tetraethylterephthalamidinium bis(tetrazolate)

The crystal structure of the title 2:1 salt of tetrazole and a substituted terephthal­amidine, C₁₆H₂₈N₄²⁺·2CHN₄^?, contains an infinite network of hydrogen bonds, with short N?N distances of 2.820 (2) and 2.8585 (19) Å between the tetrazolate anion and the amidinium cation. Involvement of the lateral N atoms of the tetrazole in the hydrogen bonding appears to be a typical binding pattern for the tetrazolate anion.     

N‐Benzoyl‐N′,N′‐dibutylselenourea and its palladium(II) complex

The crystal and molecular structures of N‐benzoyl‐N′,N′‐dibutylselenourea (HL), C₁₆H₂₄N₂OSe, and the corresponding complex bis(N‐benzoyl‐N′,N′‐dibutylselenoureato‐κ²Se,O)palladium(II), [Pd(C₁₆H₂₃N₂OSe)₂], are reported. The selenourea molecule is characterized by intermolecular hydrogen bonds between the selenoamidic H atom and the Se atom of a neighbouring molecule forming a dimer, presumably as a consequence of resonance‐assisted hydrogen bonding or π‐bonding co‐operativity. A second dimeric hydrogen bond is also described. In the palladium complex, the typical square‐planar coordination characteristic of such ligands results in a cis‐[Pd(L‐Se,O)₂] complex.     

Unusual mass spectrometric fragmentation of N,N′-diethyl-N,N′-diphenylurea

The electron impact mass spectrum of N,N′-diethyl-N,N′-diphenylurea contains the ion m/z 164 which is of low abundance at normal energy of ionizing electrons but prominent at 15-20eV. The mechanism of its formation has been revealed by means of labelled compounds. It is rationalized in terms of an unusual formation of styrene lost as a neutral molecule.     

Radical anions from N,N′-dimethylisoindigo and its methoxyderivatives

N,N′-Dimethylisoindigo and four methoxy derivatives have been synthesized and reduced to the corresponding radical anions by t-BuOK-DMSO. The epr spectra are reported and discussed.     

N,N,N′,N′‐Tetraalkylaminoazoxybenzene Derivatives; Convenient Synthesis and Mechanistic Study

N,N,N′,N′‐tetraalkyaminoazoxybenzene derivatives were conveniently prepared by the coupling of N,N‐dialkylnitrosoaniline in the presence of acetone and KOH. The reaction mechanism was proposed and investigated, and the structure of compound 3b was also confirmed by single crystal X‐ray diffractometry.     

Synthesis and characterization of N-phenylated aromatic polyureas from N,N′ -dichloroformyl-p-dianilinobenzene and N,N′ -bistrimethylsilyl-diamines

NovelN-phenylated aromatic polyureas having inherent viscosities of 0.13–0.35 dL/g were synthesized by the solution polycondensation of N,N′-dichloroformyl-p-dianilinobenzene with N,N′-bistrimethylsilyl derivatives of bis(4-aminophenyl)ether, piperazine, and p-dianilinobenzene in sulfolane. Except the polyurea containing piperazine unit, the other polyureas were amorphous and readily soluble in a variety of organic solvents such as tetrahydrofuran. The polyurea derived from p-dianilinobenzene, which has no vulnerable hydrogen on the urea linkage, did not melt below 350°C and was stable up to 450°C in air.     

N,N,N′,N′‐Tetrasubstituted Piperazinium Salts of Perfluorinated Acids

Well crystallized diquaternary piperazinium salts of perfluorocarboxylic acids can be prepared by thermal rearrangement of a primary product obtained from the appropriate fluorinated acid chloride and N,N‐dialkylamino‐ethanol. The mechanism of the ring closure step is discussed. The synthetic strategy easily gives access to structurally different piperazinium perfluorocarboxylates. The title compounds show surface activity and can be regarded as ionic amphiphiles.     

New,strong cationic hydrogels: Preparation of N,N,N′,N′‐tetraallyl piperazinium dibromide and its copolymers with N,N‐diallyl morpholinium bromide

N,N,N′,N′‐tetraallyl piperazinium dibromide (TAP) has been prepared in high yields by quaternization of N,N′‐diallyl piperazine with allyl bromide. Herein, we have described preparation of nonhydrolysable, strong, cationic hydrogels by copolymerization of TAP with N,N‐diallyl morpholinium bromide (DAM) in the presence of t‐butyl hydroperoxide as initiator in aqueous solutions. Because the monomer and crosslinker involved consist of quaternary amine functions, these hydrogels are fully cationic and do not carry hydrolysable groups. Contrary to expectations, the quaternary amine hydrogels presented do not show any super absorbency, instead dry gel particles in water undergo spontaneous disintegration with an audible bursting of the particles due to instantaneous, high osmotic pressure. Whereas, in KBr or HBr solutions, the swellings are relatively slow. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1006–1013, 2000     

N,N,N′,N′‐Tetra­methyl­ethyl­enedi­ammonium dichloride

The structure of the title compound, C₆H₁₈N₂²⁺.2Cl^?, has been determined and has a centre of symmetry. The mol­ecule has strong intermolecular hydrogen bonding between each Cl^? and an N—H bond [Cl?N = 3.012 (3) Å].     

Dimeres N-Lithium-N′,N′-bis(dimethylphenylsilyl)- und trimeres N,N′-Dilithium-N,N′-bis(dimethylphenylsilyl)hydrazid – Synthesen,Strukturen und Reaktionen

Dimeric N-Lithium-N′,N′-bis(dimethyphenylsilyl)- and trimeric N,N′-Dilithium-N,N′-bis(dimethylphenylsilyl)hydrazide – Syntheses, Structures, and Reactions Dilithiated hydrazine reacts with two equivalents chlorodimethylphenylsilane to the isomeric bis(silyl)hydrazines 1 a and 1 b . Reactions of 1 a / 1 b with one and two equivalents n-butyllithium lead to the lithium derivatives 2 and 4 . The crystal structure analyses of 2 and 4 are reported. 2 forms with difluorodiisopropylsilane the tris(silyl)hydrazine 3 . The tetrakis(silyl)hydrazines 5 and 6 are formed in reactions of 4 with trifluoromethylsilane and tetrafluorosilane.     

[N,N′‐Bis(3‐aminopropyl)ethylenediamine‐κ4N,N′,N′′,N′′′](trithiocyanurato‐κ2N,S)zinc(II) ethanol solvate

In the crystal structure of the title compound, [N,N′‐bis(3‐­amino­propyl)­ethyl­enedi­amine‐κ⁴N,N′,N′′,N′′′][1,3,5‐triazine‐2,4,6(1H,3H,5H)‐tri­thionato(2−)‐κ²N,S]­zinc(II) ethanol sol­vate, [Zn(C₈H₂₂N₄)₂(C₃HN₃S₃)]·C₂H₆O, the Zn^II atom is octa­hedrally coordinated by four N atoms [Zn—N = 2.104 (2)–2.203 (2) Å] of a tetradentate N‐donor N,N′‐bis(3‐­amino­propyl)­ethyl­enedi­amine (bapen) ligand and by two S and N atoms [Zn—S = 2.5700 (7) Å and Zn—N = 2.313 (2) Å] of a tri­thio­cyanurate(2−) (ttcH²⁻) dianion bonded as a bidentate ligand in a cis configuration. The crystal structure of the compound is stabilized by a network of hydrogen bonds.     

N,N′‐Dibenzyldithiooxamide

The title compound, alternatively known as N,N′‐di­benzyl­ethane­di­thioamide, C₁₆H₁₆N₂S₂, lies about an inversion centre and contains a planar trans‐di­thiooxamide fragment characterized by a strong intramolecular hydrogen bond between the S atom and the adjacent amide H atom in the solid state, with an S?N distance of 2.926 (1) Å. The aryl substituent is oriented orthogonal to the mean plane of the trans‐di­thiooxamide fragment due to steric hindrance and this effect is discussed.