Bis­[bis(N,N‐diethyl‐1,1‐di­seleno­car­bam­ato)copper(II)], [Cu(Se2CNEt2)2]2

The title centrosymmetric Cu^II binuclear complex, bis(μ‐N,N‐diethyl‐1,1‐di­seleno­carbamato‐Se,Se′:Se)­bis­[(N,N‐diethyl‐1,1‐di­seleno­carbamato‐Se,Se′)copper(II)], [Cu(Se₂CNEt₂)₂]₂ or [Cu₂(C₅H₁₀NSe₂)₄], is built from two symmetry‐related [Cu{Se₂CN(Et)₂}₂] units by pairs of Cu—Se bonds. The coordination geometry at the unique Cu atom is distorted square pyramidal, with Cu—Se distances in the range 2.4091 (11)—2.9095 (10) Å.     

trans‐Dichloridotetrakis(3,5‐dimethylpyridine)copper(II)

The title compound, [CuCl₂(C₇H₉N)₄], lies on a site of crystallographic 42 (D₄) symmetry in the space group P4/nnc, and is isomorphous with the Ni and Co analogues. The Cu and Cl atoms thus lie on a fourfold axis, and the 3,5‐lutidine ligands lie on twofold axes. The Cu—Cl distance is 2.7649 (7) Å and the Cu—N distance is 2.0510 (12) Å. The space group of the Co analogue is revised from Pnnn to P4/nnc.     

Temperature Influence on the Formation of Selenidoantimonates: Solvothermal Syntheses,Crystal Structures and Thermal Properties of [Ni(dien)2]2Sb2Se6, [Mn(dien)2]2(SbSe4)(Cl), [Co(dien)2]2(SbSe4)(Br), and [Co(dien)2]3(SbSe4)2

New selenidoantimonats [Ni(dien)₂]₂Sb₂Se₆ ( 1 ), [Mn(dien)₂]₂(SbSe₄)(Cl) ( 2 ), [Co(dien)₂]₂(SbSe₄)(Br) ( 3 ), and [Co(dien)₂]₃(SbSe₄)₂ ( 4 ) (dien = diethylenetriamine) were solvothermally synthesized in dien solvent at 180 °C. The crystal structure of 1 consists of two octahedral [Ni(dien)₂]²⁺ cations and a mixed‐valent [Sb₂Se₆]^4? anion. The isolated [Sb₂Se₆]^4? anion is formed by a Sb^IIISe₃ trigonal pyramid and a Sb^VSe₄ tetrahedron sharing a common corner. 2 and 3 are composed of octahedral [M(dien)₂]²⁺ cations, tetrahedral [SbSe₄]^3? anions and halide ions forming an extended network through hydrogen‐bonding interactions. In 4 the [Co(1)(dien)₂]²⁺, [Co(2)(dien)₂]²⁺ and [SbSe₄]^3? ions form layered structures via N–H···Se hydrogen bonds. The [Co(3)(dien)₂]²⁺ ion is located between the layers, and interacts with the layers by N–H···Se bonds. The synthesis and solid state structural studies on the title compounds show that the higher reaction temperature is helpful for the formation of selenidoantimonate(V) compounds in the synthesis of selenidoantimonate from the M²⁺/Sb/Se/dien system. 1 – 4 start to decompose at temperature about 210 °C in N₂ atmosphere. They lose dien ligands at a wide temperature range of 210–450 °C with multisteps for 1 – 3 and a single step for 4 .     

(1,3‐Dimethylimidazolidine‐2‐selone‐κSe)bis(1,10‐phenanthroline‐κ2N,N′)copper(II) bis(perchlorate) and bis(2,2′‐bipyridyl‐κ2N,N′)(imidazolidine‐2‐thione‐κS)copper(II) bis(perchlorate)

In the first title salt, [Cu(C₁₂H₈N₂)₂(C₅H₁₀N₂Se)](ClO₄)₂, the Cu^II centre occupies a distorted trigonal–bipyramidal environment defined by four N donors from two 1,10‐phenanthroline (phen) ligands and by the Se donor of a 1,3‐dimethylimidazolidine‐2‐selone ligand, with the equatorial plane defined by the Se and by two N donors from different phen ligands and the axial sites occupied by the two remaining N donors, one from each phen ligand. The Cu—N distances span the range 1.980 (10)–2.114 (11) Å and the Cu—Se distance is 2.491 (3) Å. Intermolecular π–π contacts between imidazolidine rings and the central rings of phen ligands generate chains of cations. In the second salt, [Cu(C₁₀H₈N₂)₂(C₃H₆N₂S)](ClO₄)₂, the Cu^II centre occupies a similar distorted trigonal–bipyramidal environment comprising four N donors from two 2,2′‐bipyridyl (bipy) ligands and an S donor from an imidazolidine‐2‐thione ligand. The equatorial plane is defined by the S donor and two N donors from different bipy ligands. The Cu—N distances span the range 1.984 (6)–2.069 (7) Å and the Cu—S distance is 2.366 (3) Å. Intermolecular π–π contacts between imidazolidine and pyridyl rings form chains of cations. A major difference between the two structures is due to the presence in the second complex of two N—H...O hydrogen bonds linking the imidazolidine N—H hydrogen‐bond donors to perchlorate O‐atom acceptors.     

Intra‐ and intermolecular Se...X (X = Se,O) interactions in selenium‐containing heterocycles: 3‐benzoylimino‐5‐(morpholin‐4‐yl)‐1,2,4‐diselenazole

In the selenium‐containing heterocyclic title compound {systematic name: N‐[5‐(morpholin‐4‐yl)‐3H‐1,2,4‐diselenazol‐3‐ylidene]benzamide}, C₁₃H₁₃N₃O₂Se₂, the five‐membered 1,2,4‐diselenazole ring and the amide group form a planar unit, but the phenyl ring plane is twisted by 22.12 (19)° relative to this plane. The five consecutive N—C bond lengths are all of similar lengths [1.316 (6)–1.358 (6) Å], indicating substantial delocalization along these bonds. The Se...O distance of 2.302 (3) Å, combined with a longer than usual amide C=O bond of 2.252 (5) Å, suggest a significant interaction between the amide O atom and its adjacent Se atom. An analysis of related structures containing an Se—Se...X unit (X = Se, S, O) shows a strong correlation between the Se—Se bond length and the strength of the Se...X interaction. When X = O, the strength of the Se...O interaction also correlates with the carbonyl C=O bond length. Weak intermolecular Se...Se, Se...O, C—H...O, C—H...π and π–π interactions each serve to link the molecules into ribbons or chains, with the C—H...O motif being a double helix, while the combination of all interactions generates the overall three‐dimensional supramolecular framework.     

catena‐Poly­[[tetrakis(2‐allyl­tetrazole‐κN4)‐tetra‐μ‐chloro‐tricopper(II)]‐di‐μ‐chloro]

In the crystal structure of the title compound, [Cu₃Cl₆(C₄H₆N₄)₄]_n, there are three Cu atoms, six Cl atoms and four 2‐allyl­tetrazole ligands in the asymmetric unit. The polyhedron of one Cu atom adopts a flattened octahedral geometry, with two 2‐allyl­tetrazole ligands in the axial positions [Cu—N4 = 1.990 (2) and 1.991 (2) Å] and four Cl atoms in the equatorial positions [Cu—Cl = 2.4331 (9)–2.5426 (9) Å]. The polyhedra of the other two Cu atoms have a square‐pyramidal geometry, with three basal sites occupied by Cl atoms [Cu—Cl = 2.2487 (9)–2.3163 (8) and 2.2569 (9)–2.3034 (9) Å] and one basal site occupied by a 2‐allyl­tetrazole ligand [Cu—N4 = 2.028 (2) and 2.013 (2) Å]. A Cl atom lies in the apical position of either pyramid [Cu—Cl = 2.8360 (10) and 2.8046 (9) Å]. The possibility of including the tetrazole N3 atoms in the coordination sphere of the two Cu atoms is discussed. Neighbouring copper polyhedra share their edges with Cl atoms to form one‐dimensional polymeric chains running along the a axis.     

Cs4BiAs3Se7: A Novel Bismuth‐Selenoarsenate with Infinite [BiAs3Se7]4– Chains Containing Two Different Anions, [AsSe3]3– and trans‐[As2Se4]4–

A new phase has been prepared by methanolothermal reaction of Cs₂CO₃, BiCl₃ and Li₃AsSe₃ at 130 °C for 36 hours. Cs₄BiAs₃Se₇ ( I ) reveals the first Bi‐selenoarsenate polyanionic chain [Bi(As₂Se₄)(AsSe₃)]^4–, consisting of Bi³⁺ ions in a distorted octahedral environment of [AsSe₃]^3– and trans‐[As₂Se₄]^4– units. The latter anion consists of a central “As₂⁴⁺” dumb‐bell whereby two Se atoms are attached to each of the As atoms. Structural Data: Space Group P2₁/n, a = 13.404(4) Å, b = 23.745(8) Å, c = 13.880(4) Å, β = 99.324(6)°, Z = 8.     

The Synthesis and Crystal Structure of NpSe3

Neptunium triselenide, NpSe₃, was synthesized in high yield by the reaction of the elements in a Sb₂Se₃ flux at 1223 K. Its structure has been determined by single‐crystal X‐ray diffraction methods. Thecompound crystallizes with two formula units in space group C$\rm^{2}_{2h}$ –P2₁/mof the monoclinic system in the TiS₃ structure type with cell constants at 100 K of a = 5.592(3) Å, b = 4.002(2) Å, c = 9.422(5) Å,β = 97.40(1) °. The asymmetric unit comprises one neptunium and three selenium atoms, each with site symmetry m. Np–Se interatomic distances range from 2.859(2) to 2.927(3) Å; the Se–Se bond length of 2.340(3) Å is typical of a single bond. The compound may thus be charge‐balanced and formulated as Np⁴⁺Se^2–Se₂^2–.     

On Polychalcogenides of Thallium with M2 Q11 Groups as a Structural Building Block. II. Tl4Ta2Se11: Synthesis,Crystal Structure,Properties and Spectroscopic Investigations of the First Polyselenide being Composed of a Discrete [Ta2Se11]4— Anion

The new ternary compound Tl₄Ta₂Se₁₁ was prepared in a melt of thallium polyselenides applying elemental tantalum. It crystallises in the triclinic space group P1¯ with a = 7.996(1) Å, b = 9.866(1) Å, c = 13.668(2) Å, α = 73.03(1)°, β = 89.21(2)° and γ = 85.72(1)°. Tl₄Ta₂Se₁₁ is the first polyselenide with discrete complex [M₂Se₁₁]^4— anions. Every Ta atom is in a sevenfold environment of Se atoms to form a distorted pentagonal bi‐pyramid. The two TaSe₇ polyhedra have a face in common thus yielding the [Ta₂Se₁₁]^4— unit. In the structure, the anions are well separated by the Tl¹⁺ cations. An assignment of the different vibration modes in the IR and Raman spectra is given based on density functional calculations.     

Bis(N,N‐diethyl‐1,1‐di­seleno­carbam­ato‐Se)­selenium, [(Se2CNEt2)2Se]

The poly­seleno title compound, bis(N,N‐diethyl­seleno­carbamoyl) tri­selenide, [(Se₂CNEt₂)₂Se] or C₁₀H₂₀N₂Se₅, is obtained from the disproportion of sodium N,N‐diethyl‐1,1‐di­seleno­carbamate. An Se atom connects two N,N‐diethyl‐1,1‐di­seleno­carbamate groups with Se—Se distances in the range 2.4500 (11)–2.8601 (12) Å     

Syntheses and Crystal Structures of Rb2B2Se7, Tl2B2Se7, Cs3B3Se10, and Tl3B3Se10: New Perseleno‐selenoborates with Polymeric Anionic Chains

The perseleno‐selenoborates Rb₂B₂Se₇ and Cs₃B₃Se₁₀ were prepared from the metal selenides, amorphous boron and selenium, the thallium perseleno‐selenoborates Tl₂B₂Se₇ and Tl₃B₃Se₁₀ directly from the elements in evacuated carbon coated silica tubes by solid state reactions at temperatures between 920 K and 950 K. All structures were refined from single crystal X‐ray diffraction data. The isotypic perseleno‐selenoborates Rb₂B₂Se₇ and Tl₂B₂Se₇ crystallize in the monoclinic space group I 2/a (No. 15) with lattice parameters a = 12.414(3) Å, b = 7.314(2) Å, c = 14.092(3) Å, β = 107.30(3)°, and Z = 4 for Rb₂B₂Se₇ and a = 11.878(2) Å, b = 7.091(2) Å, c = 13.998(3) Å, β = 108.37(3)° with Z = 4 for Tl₂B₂Se₇. The isotypic perseleno‐selenoborates Cs₃B₃Se₁₀ and Tl₃B₃Se₁₀ crystallize in the triclinic space group P1 (Cs₃B₃Se₁₀: a = 7.583(2) Å, b = 8.464(2) Å, c = 15.276(3) Å, α = 107.03(3)°, β = 89.29(3)°, γ = 101.19(3)°, Z = 2, (non‐conventional setting); Tl₃B₃Se₁₀: a = 7.099(2) Å, b = 8.072(2) Å, c = 14.545(3) Å, α = 105.24(3)°, β = 95.82(3)°, γ = 92.79(3)°, and Z = 2). All crystal structures contain polymeric anionic chains of composition ([B₂Se₇]^2–)_n or ([B₃Se₁₀]^3–)_n formed by spirocyclically fused non‐planar five‐membered B₂Se₃ rings and six‐membered B₂Se₄ rings in a molar ratio of 1 : 1 or 2 : 1, respectively. All boron atoms have tetrahedral coordination with corner‐sharing BSe₄ tetrahedra additionally connected via Se–Se bridges. The cations are situated between three polymeric anionic chains leading to a nine‐fold coordination of the rubidium and thallium cations by selenium in M₂B₂Se₇ (M = Rb, Tl). Coordination numbers of Cs⁺ (Tl⁺) in Cs₃B₃Se₁₀ (Tl₃B₃Se₁₀) are 12(11) and 11(9).     

Tetraammine(selenito‐O,O′)cobaltate(III) nitrate monohydrate

The title compound crystallizes as the mono­hydrate, [Co(SeO₃)(NH₃)₄]NO₃·H₂O. The crystallographic mirror symmetry coincides with the molecular symmetry; the mirror plane passes through the cation, anion and water mol­ecule. The CoN₄O₂ octahedron is distorted, with the selenito group acting as a bidentate ligand through two bridging O atoms to the cobalt. The coordinated Se—O distance is 1.742 (2) Å, whereas the uncoordinated Se—O distance is 1.646 (3) Å. A three‐dimensional hydrogen‐bonded network exists between [Co(SeO₃)(NH₃)₄]NO₃ and the water mol­ecule. The nitrate anion and water mol­ecule form open pores in the structure when hydrogen bonded to two neighboring [Co(SeO₃)(NH₃)₄]⁺ cations. Selenium participates in two types of relatively close intermolecular interactions with neighboring charged species (Se?N1 and Se?O3), but does not participate in an interaction with a neighboring O2 atom, the nearest contact distance being 4.638 (3) Å.     

[2,2′‐(1,3,5,8,10,12‐Hexaazacyclotetradecane‐3,10‐diyl)diethanol‐κ4N1,N5,N8,N12]bis(thiocyanato‐κS)copper(II)

In the crystal structure of the title compound, [Cu(NCS)₂(C₁₂H₃₀N₆O₂)], the Cu atom lies on an inversion centre and has an elongated octahedral coordination, with Cu—N distances of 2.004 (2) and 2.015 (2) Å, and a Cu—S distance of 2.9696 (10) Å. The 2,2′‐ethanol chains are axially oriented. The mol­ecules are linked to form a three‐dimensional network via O—H?N, N—H?O and N—H?S hydrogen bonds.     

1,3‐Bis[2‐(dimethylaminomethyl)phenyl]triselenide

The title compound, C₁₈H₂₄N₂Se₃, consists of discrete molecules; owing to the presence of strong intramolecular N...Se interactions [N...Se = 2.671 (4) and 2.873 (4) Å], the chalcogen Se atoms of the angular Se₃ chain exhibit different coordination geometries, i.e. the terminal Se atoms are tricoordinated and exhibit a T‐shaped environment of the CNSe₂ core [N...Se—Se = 173.73 (9) and 172.29 (9)°], while the central Se atom is dicoordinated to the other two Se atoms, with an Se—Se—Se angle of 108.32 (2)°.     

Potassium sodium tin selenide,K3NaSn3Se8

The title compound, tripotassium sodium tritin octaselenide, K₃NaSn₃Se₈, has a molecular (zero‐dimensional) structure containing trimeric [Sn₃Se₈]^4? units which consist of three edge‐sharing SnSe₄ tetrahedra. The [Sn₃Se₈]^4? anions and the tetrahedrally coordinated Na⁺ cations are arranged in an alternating fashion along the c axis to form SiS₂‐like chains, which are then separated by eight‐coordinate K⁺ cations. The Sn—Se bond distances are normal, being in the range 2.477 (1)–2.612 (1) Å.     

5‐n‐Butylpyridine‐2‐carboxylate–copper(II) and –iron(III) complexes

In trans‐bis(5‐n‐butyl­pyridine‐2‐carboxyl­ato‐κ²N,O)­bis­(methanol‐κO)copper(II), [Cu(C₁₀H₁₂NO₂)₂(CH₄O)₂], the Cu atom lies on a centre of symmetry and has a distorted octahedral coordination. The Cu—O(methanol) bond length in the axial direction is 2.596 (3) Å, which is much longer than the Cu—­O(carboxylate) and Cu—N distances in the equatorial plane [1.952 (2) and 1.977 (2) Å, respectively]. In mer‐tris(5‐n‐bu­tyl­pyridine‐2‐carboxyl­ato‐κ²N,O)­iron(III), [Fe(C₁₀H₁₂NO₂)₃], the Fe atom also has a distorted octahedral geometry, with Fe—O and Fe—N bond‐length ranges of 1.949 (4)–1.970 (4) and 2.116 (5)–2.161 (5) Å, respectively. Both crystals are stabilized by stacking interactions of the 5‐n‐butyl­pyridine‐2‐carboxyl­ate ligand, although hydrogen bonds also contribute to the stabilization of the copper(II) complex.     

Bis(1,2‐diaminobenzene‐N)­bis(1,1,1,5,5,5‐hexa­fluoro­pen­tane‐2,4‐dion­ato‐O,O′)­iron(II), ‐cobalt(II) and ‐nickel(II) at low temperature

Addition of 1,2‐phenylenediamine to solutions ofbis(1,1,1,5,5,5‐hexafluoropentane‐2,4‐dionato‐O,O′)cobalt(II),‐iron(II) and ‐nickel(II) resulted in crystals containing centrosymmetric octahedral complexes with two amines per metal atom. In all three iso­structural complexes, i.e. [M(C₅HF₆O₂)₂(C₆H₈N₂)₂] where M = Fe, Cu and Ni, the two C—N bonds differ significantly in length by an average of 0.031 (3) Å. The phenyl C—C bonds display a pattern of small differences, the C—C bond between the amines being longer than the shortest phenyl C—C bonds by an average of 0.022 (4) Å.     

Diaqua{6,6′‐dimethoxy‐2,2′‐[propane‐1,3‐diylbis(nitrilomethylidyne‐N)]diphenolato‐O,O′}nickel(II)

In the title compound, [Ni(C₁₉H₂₀N₂O₄)(H₂O)₂], the Ni atom has a distorted octahedral coordination geometry in which the tetradentate Schiff base ligand acts as a cis‐N₂O₂ donor defining an equatorial plane, and water mol­ecules occupy the axial positions. The two parts of the mol­ecule are related by a mirror plane that passes through the Ni atom and is perpendicular to the equatorial plane. The angular distortions from normal octahedral geometry are in the range 1–6°, and the equatorial plane, defined by the donor atoms of the Schiff base, is almost square planar. The six‐membered ring comprising the Ni, the imine N and the propyl­ene C atoms adopts a half‐chair conformation. The Ni—O [2.017 (2) Å] and Ni—N [2.071 (2) Å] distances are within the ranges expected for high‐spin octahedral nickel complexes.     

Tris(8‐quinolinolato‐N,O)­cobalt(III) ethanol solvate

In the crystal of the title complex, [Co(C₉H₆NO)₃]·C₂H₅OH, the central Co atom has a distorted octahedral coordination comprised of three N atoms and three O atoms from the three 8‐quinolinolato ligands. The three Co—O bond distances are in the range 1.887 (2)–1.910 (2) Å, while the three Co—N bond distances range from 1.919 (2) to 1.934 (2) Å. The solvent ethanol mol­ecule forms an intermolecular O—H?O hydrogen bonding with a quinolinolato ligand.     

Low‐dimensional compounds containing cyano groups. II. catena‐Poly[[(2,2′‐bipyridine‐κ2N:N′)(dicyanamido‐κN)copper(II)]‐μ‐dicyanamido‐κ2N:N′]

The crystal structure of the title compound, [Cu(C₂N₃)₂(C₁₀H₈N₂)]_n, is formed by neutral zigzag chains of the [–NC–N–CN–Cu{(bpy)N(CN)₂}–NC–N–CN–] type run­ning along the c axis (bpy is 2,2′‐bi­pyridine). The Cu atoms in the chains are pentacoordinated in the form of a distorted tetragonal pyramid, with a CuN₅ chromophore. The coordination sites are occupied by two N atoms of one bpy mol­ecule in the basal plane [Cu—N 2.018 (4) and 2.025 (2) Å] and by three terminal N atoms of two dicyan­amide ligands. One of the dicyan­amide ligands is coordinated in a monodentate fashion through a nitrile N atom in the basal plane [Cu—N 1.963 (4) Å]. The second acts as an end‐to‐end bridging ligand to a neighbouring Cu atom and is coordinated by one nitrile N atom in the basal plane [Cu—N 2.001 (2) Å], while the second nitrile N atom occupies the apical position [Cu—N 2.159 (2) Å] and originates from the bridge connecting another Cu atom. The shortest intrachain Cu?Cu distance is 8.212 (1) Å, as a consequence of the large bridging ligand, whereas the minimum interchain distance between Cu atoms is only 5.77 (7) Å, because of the interdigitation of the chains.