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.     

{μ‐N,N′‐Bis[2‐(dimethylamino)ethyl]oxamidato(2–)‐κ6N,N′,O′:N′′,N′′′,O}bis[(2,2′‐bipyridine‐κ2N,N′)copper(II)] bis(perchlorate)

In the crystal structure of the title complex, [Cu₂(C₁₀H₂₀N₄O₂)(C₁₀H₈N₂)₂](ClO₄)₂, the deprotonated dmaeoxd²⁻ ligand {H₂dmaeoxd is N,N′‐bis[2‐(dimethylamino)ethyl]oxamide} occupies an inversion centre at the mid‐point of the central C—C bond and is thus in a trans conformation. The two Cu^II atoms are located in slightly distorted square‐based pyramidal environments. The binuclear units interact with each other viaπ–π interactions to form a one‐dimensional chain extending in the c direction.     

First [4+2] Cycloadditions Involving the Olefinic Bond of an ‘Aldoketeniminium Salt’ (=N‐Alk‐1‐enylideneaminium Salt)

‘Keteniminium triflates’ (=N‐alk‐1‐enylideneaminium trifluoromethanesulfonates; [MeN(Ts)CHC NR¹(R²)]⁺TfO⁻) generated in situ from N^α‐tosylsarcosinamides MeN(Ts)CH₂CONR¹(R²) unexpectedly react with cyclopenta‐1,3‐diene and cyclohexa‐1,3‐diene to give Diels–Alder reactions across the CC bond of the cumulene. The use of N^α‐tosylsarcosinamides derived from chiral pyrrolidines allows the direct preparation of trinorbornenone derivative 6 in high enantiomer purity.     

A two‐dimensional layer in N,N′‐bis[2‐(hydroxymethyl)benzyl]ethylenediamine and a three‐dimensional network in N,N′‐bis[2‐(hydroxymethyl)benzyl]ethylenediammonium bis(perchlorate)

In both title compounds, C₁₈H₂₄N₂O₂, (Ia), and C₁₈H₂₆N₂O₂²⁺·2ClO₄⁻, (II), respectively, the two aryl rings are strictly parallel, with an inversion centre lying at the mid‐point of each central CH₂—CH₂ bond. Molecules in (Ia) are linked into two‐dimensional layers by N—H...O hydrogen bonds. The component ions in (II) are joined together by a combination of N/O/C—H...O hydrogen bonds and C—H...π and anion...π interactions, forming a three‐dimensional network. A structural understanding of (Ia) and (II) may provide some useful information about how and why their metal–organic complexes display various biological activities and function in catalytic processes.     

Intramolekulare Cycloaddition von [1,1′-Binaphthyl]-2,2′-bis(allylamin)

Intramolecular cycloaddition of [1,1′-binaphthyl]-2,2′-bis(allylamine) Unlike the 1,1′-binaphthyl-2,2′-bis(allylether) the corresponding [1,1′-binaphthyl]-2,2′-bis(allylamine) (1) upon heating to 230° in mesitylene undergoes thermal decomposition only. However, when 1 is heated in a mixture of 2-methylaminoethanol and water, besides 3 the policyclic ketones 4 and 5 are formed in isolated yields of 28 and 10%, respectively (Scheme 1). Intermediates are the imines corresponding to 4 and 5 which are hydrolysed under the reaction conditions rather than decomposed. The imines are formed by a intramolecular Diels-Alder reaction, in which the double bond of one N-allylgroup reacts with the naphthalene ring of the second half of the molecule. The policyclic ketones 4 and 5 are characterized as acetates 6 and 7 , respectively, and as the acetylated reduced products 11 , and 12 and 13 , respectively. The constitutions of all compounds are derived from spectroscopic data, chiefly from the ¹H-NMR. spectra.     

Bis[1,1′‐bis(diphenylphosphino)ferrocenium] hexadecachlorotetraantimony(III) ethanol solvate

In the title compound, [Fe(C₁₇H₁₄P)₂]₂[Sb₄Cl₁₆]·C₂H₆O, the Fe atoms lie on inversion centres and the pairs of cyclopentadienyl rings are consequently in a fully staggered conformation. The centrosymmetric anionic clusters formed by [Sb₄Cl₁₆]^4? are surrounded by the cations and are held together by weak C—H?Cl interactions. These formations stack along the a axis to form columns, and the columns are interconnected by another weak C—H?Cl interaction along the b axis.     

Two concomitant polymorphs of N,N′‐bis[4‐(diethylamino)phenyl]terephthaldiamide

The title compound, C₂₈H₃₄N₄O₂, crystallizes simultaneously as a monoclinic, (Im), and a (twinned) triclinic polymorph, (It), from d₆‐dimethyl sulfoxide. Polymorph (It) (P, Z = 1) displays the standard `ladder' packing for this group of compounds, with neighbouring inversion‐symmetric molecules related by translation and connected by hydrogen bonds of the form N—H...O=C. Polymorph (Im) (Cc, Z = 4) has no imposed symmetry; there are three independent hydrogen bonds, one classical N—H...O=C and a bifurcated system with N—H...O=C augmented by a short C—H...O=C interaction. Each molecule is thereby linked to four neighbouring molecules, two lower and two higher, so that a crosslinked three‐dimensional pattern is formed rather than the standard ladder.     

The heterometallic cadmium–silver complex cis‐bis[dicyanidoargentato(I)‐κN]bis(5,5′‐dimethyl‐2,2′‐bipyridyl‐κ2N,N′)cadmium(II) monohydrate

In the title complex, [Ag₂Cd(CN)₄(C₁₂H₁₂N₂)₂]·H₂O or cis‐[Cd{Ag(CN)₂}₂(5,5′‐dmbpy)₂]·H₂O, where 5,5′‐dmbpy is 5,5′‐dimethyl‐2,2′‐bipyridyl, the asymmetric unit consists of a discrete neutral [Cd{Ag(CN)₂}₂(5,5′‐dmbpy)₂] unit and a solvent water molecule. The Cd^II cation is coordinated by two bidentate chelate 5,5′‐dmbpy ligands and two monodentate [Ag^I(CN)₂]⁻ anions, which are in a cis arrangement around the Cd^II cation, leading to an octahedral CdN₆ geometry. The overall structure is stabilized by a combination of intermolecular hydrogen bonding, and Ag^I...Ag^I and π–π interactions, forming a three‐dimensional supramolecular network.     

[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.     

Synthesis of 1,4‐Diazabutadienes (=N,N′‐Ethane‐1,2‐diylidenebis[amines]) by Grinding

A simple and convenient method for the synthesis of 1,4‐diazabutadienes (=N,N′‐ethane‐1,2‐diylidenebis[amines]) by grinding glyoxal (=ethanedial) or an α‐diketone and anilines (=benzenamines) in the presence of TsOH in a mortar with a pestle is described. By this way, 1,4‐diazabutadienes were obtained in good to excellent yields.     

Crystallographic report: (4,4′‐Bipyridine)bis[bis(N,N‐diethyldithiocarbamato)zinc(II)]

The structure of [Zn(S₂CNEt₂)₂]₂(4,4′‐bipy) shows two independent dimeric molecules, one located about a centre of inversion, the other lying on a two fold axis containing the zinc atoms. Bidentate coordination by the dithiocarbamate ligands and a distorted square pyramidal geometry are found for two of zinc atoms whereas for the third zinc atom, the geometry is intermediate between square pyramidal and trigonal bipyramidal, a result that underscores the flexibility of coordination in these systems. Copyright © 2003 John Wiley & Sons, Ltd.     

Bis[μ‐1,2‐bis(2‐pyridyl)ethyne‐κ2N:N′]bis[aquadinitratocadmium(II)]

Two twisted 1,2‐bis(2‐pyridyl)­ethyne ligands bridge two Cd²⁺ centers in the C₂‐symmetric title complex, [Cd₂(NO₃)₄(μ‐C₁₂H₈N₂)₂(H₂O)₂]. The bridging ligands arch across one another creating a `zigzag loop' molecular geometry. Two nitrate ions and a water mol­ecule complete the irregular seven‐coordinate Cd‐atom environment. The dihedral angles between the equivalent pyridyl ring planes of the two independent ligands are 67.2 (1)°. O_water—H⃛O_nitrate hydrogen bonding creates two‐dimensional layers parallel to the ab plane.     

Bis[N,N′‐bis(2‐nitrocinnamaldehyde)phenylenediimine]copper(I) Perchlorate

The complex [Cu(nitroca₂ph)₂]ClO₄, where nitroca₂ph is N,N′‐bis(2‐nitrocinnamaldehyde)phenylenediimine, crystallizes in the triclinic space group with a = 13.167(1), b = 13.209(1), c = 14.465(1) Å, α = 83.209(9)°, β = 68.438(2)°, γ = 70.803(2)°, V = 2209.4(3) ų, Z = 2, D_calc = 1.527 mg/m³. The coordination polyhedron about the Cu(I) atom is best described as a distorted tetrahedron. 2‐nitroca₂en acts as a bidentate ligand coordinating via two N atoms to the copper. The four Cu–N distances are 2.04 (2), 2.038(2), 2.046(2), and 2.062(2) Å.     

fac‐Tricarbonyl[bis(2‐pyridylmethyl) ether‐N,O,N′]molybdenum(0)

Reaction of bis(2‐pyridylmethyl) ether with [Mo(CO)₃­(Me­CN)₃] in MeCN gives the title compound, [Mo(C₁₂H₁₂‐N₂O)(CO)₃], (I), as a yellow crystalline product. Compound (I) has been characterized by ¹H NMR and IR spectroscopy, and single‐crystal X‐ray crystallography. In contrast with other examples of low‐valent early transition metal complexes of ethers, the ether linkage of (I) appears relatively inert. Nevertheless, the weak donor property of the ether ligand is evidenced by a trans effect manifested as a short Mo—CO bond length for the carbonyl ligand trans to the ether ligand.     

Die Reduktion von Azulen mit Natrium zum Kontaktionen-Tripel [Dinatrium-(1,1′,6,6′-Tetrahydro-6,6′-bi(azulen)-1,1′-diid)–bis (diglyme)]∞

The Sodium Reduction of Azulene to the Contact-Ion Triple [Disodium-(1,1′,6,6′-Tetrahydro-6,6′-bi(azulene)-1,1′-diide)–bis(diglyme)]_∞ Colorless air-sensitive single crystals can be grown from a diglyme solution after the reduction of azulene by a Na-metal mirror. Structure determination at 150 K reveals a dimer dianion, in which the seven-membered rings are connected in 6,6′-positions and doubly diglyme-solvated Na⁺ counter cations η⁵-coordinate to the five-membered rings. Based on preceding cyclovoltammetric measurements in aprotic azulene solutions as well as on extensive MNDO enthalpy of formation calculations, a proposal is forwarded how possibly the contact ion triple is formed along a microscopic pathway.     

N,N′‐Dimethylpyrazinediium bis(tetrafluoroborate) and N,N′‐diethylpyrazinediium bis(tetrafluoroborate): new examples of anion–π triads

Crystallization of N,N′‐dimethylpyrazinediium bis(tetrafluoroborate), C₆H₁₀N₂²⁺·2BF₄⁻, (I), and N,N′‐diethylpyrazinediium bis(tetrafluoroborate), C₈H₁₄N₂²⁺·2BF₄⁻, (II), from dried acetonitrile under argon protection has permitted their single‐crystal studies. In both crystal structures, the pyrazinediium dications are located about an inversion center (located at the ring center) and each pyrazinediium aromatic ring is π‐bonded to two centrosymmetrically related BF₄⁻ anions. Strong anion–π interactions, as well as weak C—H...F hydrogen bonds, between BF₄⁻ and pyrazinediium ions are present in both salts.     

Benzyl N,N‐bis[2‐(pentafluoroanilino)ethyl]carbamate

The title compound, C₂₄H₁₇F₁₀N₃O₂, exhibits intramolecular N—H...O hydrogen bonding, as well as intramolecular Ar...Ar^F face‐to‐face interactions. The molecules are linked together by N—H...F—C hydrogen bonds, forming chains parallel to the a axis. Adjacent symmetry‐related chains are combined in double zipper‐like ribbons by parallel Ar^F...Ar^F offset π‐stacking interactions.     

μ‐2,2′,6,6′‐Tetramethyl‐4,4′‐bipyridine‐κ2N1:N1′‐bis[(diethylenetriamine‐κ3N,N′,N′′)palladium(II)] tetranitrate

The title compound, [Pd₂(C₄H₁₃N₃)₂(C₁₄H₁₆N₂)](NO₃)₄, comprises discrete tetracationic dumbbell‐type dinuclear complex molecules and noncoordinating nitrate anions. Two Pd(dien)²⁺ moieties (dien is diethylenetriamine) are joined by the rigid linear exo‐bidentate bridging 2,2′,6,6′‐tetramethyl‐4,4′‐bipyridine ligand to form the dinuclear complex, which lies across a centre of inversion in the space group P2₁/n, so that the rings in the 2,2′,6,6′‐tetramethyl‐4,4′‐bipyridine bridging ligand are parallel. In the crystal, the primary and secondary amino groups of the dien ligand act as hydrogen‐bond donors towards the nitrate anions to form a three‐dimensional hydrogen‐bond network.