Dicarbonyldi‐μ‐chloro‐cis,cis‐η4‐1,5‐cyclo­octa­dienedirhodium(I)

The title compound, dicarbonyl‐1κ²C‐di‐μ‐chloro‐1:2κ⁴Cl‐[cis,cis‐2(η⁴)‐1,5‐cyclo­octa­diene]­di­rhodium(I), [Rh₂Cl₂(C₈H₁₂)(CO)₂], consists of a di­chloro‐bridged dimer of rhodium, with a non‐bonded Rh?Rh distance of 3.284 (2) Å. One Rh atom is coordinated to two carbonyl ligands, while the other Rh atom is coordinated to the cyclo­octa­diene moiety.     

Azido­[1,1′‐bis­(di­phenyl­phosphino)­ferrocene](penta­methyl­cyclo­penta­dienyl)­rhodium(III) hexa­fluoro­phosphate

In the title compound, azido‐2κN‐bis­[μ‐(1η⁵:2κP)‐di­phenyl­phosphino­cyclo­penta­dienyl][2(η⁵)‐penta­methyl­cyclo­penta­di­enyl]­iron(III)­rhodium(III) hexa­fluoro­phosphate, [{Rh(C₁₀H₁₅)(N₃)}{Fe(μ‐C₁₇H₁₄P)₂}]PF₆ or [FeRh(C₁₀H₁₅)(μ‐C₁₇H₁₄P)₂(N₃)]PF₆, the coordination sphere of Rh^III can be described as pseudo‐tetrahedral, composed of two P atoms from a 1,1′‐bis­(di­phenyl­phosphino)­ferrocene (dppf) ligand, an azido N atom and the centroid of the ring of a C₅Me₅ (Cp*) ligand. The two cyclo­penta­dienyl rings in the dppf moiety adopt an eclipsed conformation. The Rh⋯Fe distance is 4.340 (2) Å.     

A ferrocenyl‐substituted pseudo­titanocene complex

The title compound, (η⁵‐cyclo­penta­dienyl)[(1,2,3,4,5‐η)‐4‐ferro­cenyl‐1,2,5,6‐tetrakis­(tri­methyl­silyl)­cyclo­hexa‐2,4‐dien‐1‐yl]­titanium(II), [TiFe(C₅H₅)₂(C₂₃H₄₂Si₄)] or [Ti{η⁵‐C₆H₂{Fe­(η⁵‐C₅H₄)(η⁵‐C₅H₅)}{Si(CH₃)₃}₄}(η⁵‐C₅H₅)], possesses two directly linked metallocene units that subtend an angle of 52.9 (1)° (defined by the least‐squares planes of the directly connected π‐ligands) associated with the steric requirements of the bulky tri­methyl­silyl substituents. The cyclo­hexa­dienyl ligand adopts an envelope conformation; the perpendicular distance of its η⁵‐plane to the Ti atom is 1.512 (1) Å.     

A new optically pure half‐sandwich Cp–Ru diphosphine complex with a chiral metal centre, (S)‐Ru(η5‐C5H5)(EPHOS)Cl {EPHOS is (+)‐(1R,2S)‐2‐[(diphenylphosphino)methylamino]‐1‐phenylpropyl diphenylphosphinite}

The crystal structure of the title compound, chloro(η⁵‐cyclopenta­dienyl){(1R,2S)‐2‐[(di­phenyl­phosphino)­methyl­amino]‐1‐phenyl­propyl di­phenyl­phosphinite‐κ²P,P′}ruthenium(II), [Ru(C₅H₅)Cl(C₃₄H₃₃NOP₂)], is reported. The pseudo‐octa­hedral complex is chiral and the configuration at the Ru atom is S. The seven‐membered metallacycle adopts a boat‐like conformation.     

[(η5‐C5R5)TiCl2(η5‐C5H4SiMe2)]2O·nCH2Cl2

The first title metallocene, 1,3‐bis(dichlorotitanocene)‐1,1,3,3‐tetramethyldisiloxane dichloromethane solvate, [(η⁵‐C₅H₅)­TiCl₂­(η⁵‐C₅H₄­Si­Me₂)]₂O·­CH₂Cl₂, (I), crystallizes in space group P2₁/c. Compound (I) represents the first crystal structure of a bimetallic siloxy‐bridged titanocene. The geometric parameters of (I) are similar to those of the parent titanocene; however, the disiloxane substituents adopt an unexpected eclipsed conformation. The second title metallocene, 1,3‐bis­[(penta­methyl­cyclo­penta­dienyl)­(cyclo­penta­dien­yl)­titanium dichloride]‐1,1,3,3‐tetra­methyl­disiloxane, [(η⁵‐C₅‐Me₅)­TiCl₂­(η⁵‐C₅H₄­Si­Me₂)]₂O, (II), represents the second crystal structure of a bimetallic siloxy‐bridged titanocene and crystallizes in the space group P2₁/n. Compound (I) possesses non‐crystallographic twofold molecular symmetry and both metal centers adopt pseudo‐tetrahedral geometries. The geometric parameters of (II) are similar to those of the mixed titanocene Cp*CpTiCl₂ (Cp* = C₅Me₅) and the disiloxane substituents adopt a staggered conformation.     

Bis(acesulfamato‐κO4)diaqua­bis­(3‐methyl­pyridine‐κN)nickel(II)

In the crystal structure of the title compound [systematic name: diaqua­bis(6‐methyl‐2,2‐dioxo‐1,2,3‐oxathia­zin‐4‐olato‐κO⁴)bis­(3‐methyl­pyridine‐κN)nickel(II)], [Ni(C₄H₄NO₄S)₂(C₆H₇N)₂(H₂O)₂], the Ni^II centre resides on a centre of symmetry and has a distorted octa­hedral geometry. The basal plane is formed by two carbonyl O atoms of two monodentate trans‐oriented acesulfamate ligands and two trans aqua ligands. The axial positions in the octa­hedron are occupied by two N atoms of two trans pyridine ligands. Mol­ecules are stacked in columns running along the a axis. There are π–π stacking inter­actions between the mol­ecules in each column, with a distance of 3.623 (2) Å between the centroids of the pyridine rings. There are also O—H⋯O inter­actions between the columns.     

[2‐(Imidazol‐4‐yl)ethylamine]{[2‐(imidazol‐4‐yl)ethyl][(1‐methylimidazol‐2‐yl)methyl]amine}copper(II) diperchlorate

In the title mononuclear complex, [Cu(C₅H₉N₃)(C₁₀H₁₅N₅)](ClO₄)₂, the Cu^II centre is surrounded by two N‐donor ligands, which impose a square‐pyramidal environment on the metal. The new tridentate ligand [2‐(imidazol‐4‐yl)­ethyl]­[(1‐methyl­imidazol‐2‐yl)­methyl]­amine (HISMIMA) lies in the basal plane, while the hist­amine ligand occupies the apical and one of the basal positions around the Cu^II ion.     

η5‐(3)‐1‐Methyl‐1,2‐dicarbollyl‐η5‐2′,5′‐dimethylpyrrolylcobalt(III)

In the title compound, (η⁵‐2,5‐di­methyl­pyrrolyl)[(7,8,9,10,11‐η)‐7‐methyl‐7,8‐dicarba‐nido‐undecaborato]­cobalt(III), [3‐Co{η⁵‐[2,5‐(CH₃)₂‐NC₄H₂]}‐1‐CH₃‐1,2‐C₂B₉H₁₀] or [Co(C₃H₁₃B₉)(C₆H₈N)], the Co^III atom is sandwiched between the pentagonal faces of the pyrrolyl and dicarbollide ligands, resulting in a neutral mol­ecule. The C—C distance in the dicarbollide cage is 1.649 (3) Å.     

Intermolecular stacking in pyrazolo[3,4‐d]pyrimidine‐based pentamethylene‐linked flexible ­molecules

The crystal structures of 1‐{5‐[4,6‐bis­(methyl­sulfanyl)‐2H‐py­razolo­[3,4‐d]­pyrimidin‐2‐yl]­pentyl}‐6‐methyl­sulfanyl‐4‐(pyr­rolidin‐1‐yl)‐1H‐pyrazolo­[3,4‐d]­pyrimidine, C₂₂H₂₉N₉S₃, and 6‐methyl­sulfanyl‐1‐{5‐[6‐methyl­sulfanyl‐4‐(pyrrolidin‐1‐yl)‐2H‐pyrazolo­[3,4‐d]­pyrimidin‐2‐yl]­pentyl}‐4‐(pyrrolidin‐1‐yl)‐1H‐pyrazolo­[3,4‐d]­pyrimidine, C₂₅H₃₄N₁₀S₂, which differ in having either a pyrrolidine substituent or a methylsulfanyl group, show intermolecular stacking due to aromatic π–π interactions between the pyrazolo­[3,4‐d]­pyrimidine rings.     

Hydrogen bonding and π–π stacking in methyl­aminium 4′,7‐dihydroxy­isoflavone‐3′‐sulfonate dihydrate and hexa­aqua­iron(II) bis­(4′,7‐diethoxy­isoflavone‐3′‐sulfonate) tetra­hydrate

In methyl­aminium 4′,7‐dihydroxy­isoflavone‐3′‐sulfonate dihydrate, CH₆N⁺·C₁₅H₉O₇S⁻·2H₂O, 11 hydrogen bonds exist between the methyl­aminium cations, the iso­flavone‐3′‐sulfonate anions and the solvent water mol­ecules. In hexa­aqua­iron(II) bis­(4′,7‐diethoxy­isoflavone‐3′‐sulfonate) tetra­hydrate, [Fe(H₂O)₆](C₁₉H₁₇O₇S)₂·4H₂O, 12 hydrogen bonds exist between the centrosymmetric [Fe(H₂O)₆]²⁺ cation, the isoflavone‐3′‐sulfonate anions and the solvent water mol­ecules. Additional π–π stacking inter­actions generate three‐dimensional supramolecular structures in both compounds.     

Tri­benzyl{η5‐[2‐(p‐tolyl)­prop‐2‐yl]­cyclo­penta­dienyl}­zirconium

The title compound, [Zr(C₇H₇)₃(C₁₅H₁₇)], (I), crystallizes from light petroleum with two independent mol­ecules in the asymmetric unit. Whereas in the parent mol­ecule, Zr(η⁵‐C₅H₅)(CH₂Ph)₃, all three Zr—CH₂Ph angles are equal, in (I), they differ significantly. In spite of their different environments, both independent mol­ecules in (I) exhibit a small, an expected, and a large Zr—CH₂Ph angle. The angles are similar to those of the closely related tri­benzyl­[η⁵‐(benzyl­di­methyl­silyl)­cyclo­penta­dienyl]­zirconium complex. The smallest Zr—CH₂Ph angle and the consequently relatively short Zr?C_ipso distance are indicative of η²‐bonding of the benzyl group.     

(Borohydrido)(18‐crown‐6)potassium and (borohydrido)(dibenzo‐18‐crown‐6)(tetra­hydro­furan)potassium

In the two compounds (borohydrido)(1,4,7,10,13,16‐hexa­oxacyclo­octa­decane‐κ⁶O)potassium, [K(BH₄)(C₁₂H₂₄O₆)], (I), and (borohydrido)(1,4,7,10,13,16‐hexa­oxa‐2,3:11,12‐di­benzo­cyclo­octa­deca‐2,11‐diene‐κ⁶O)(tetra­hydro­furan)­potassium, [K(BH₄)(C₄H₈O)(C₂₀H₂₄O₆)], (II), the K atom is bound to the six O atoms of the crown ether and to a tridentate borohydride group, with further coordination to a tetra­hydro­furan mol­ecule in (II). The alkali metal ion environment is thus distorted hexa­gonal–pyramidal in (I) and bipyramidal in (II).     

Thia­mine tetra­phenyl­borate monohydrate: a two‐dimensional hydrogen‐bonded network with (4,4)‐topology

The title compound, 3‐[(4‐amino‐2‐methyl­pyrimidin‐5‐yl)­meth­yl]‐5‐(2‐hydroxy­eth­yl)‐4‐methyl­thia­zolium tetra­phenyl­borate monohydrate, C₁₂H₁₇N₄OS⁺·C₂₄H₂₀B⁻·H₂O, is a salt in which the thiamine cations are linked by hydrogen bonds into a two‐dimensional network having (4,4)‐topology. The stacked sheets form channels, which are occupied by the anions; the cations and anions are linked by C—H⋯π(arene) hydrogen bonds.     

(Z)‐2‐Methylbuten‐1‐yl(aryl)iodonium trifluoromethanesulfonates containing electron‐withdrawing groups on the aryl moiety

The crystal structures of [(Z)‐2‐methyl­but‐1‐en‐1‐yl]­[4‐(tri­fluoro­methyl)­phenyl]­iodo­nium tri­fluoro­methane­sulfonate, C₁₂H₁₃F₃I⁺·CF₃O₃S^?, (I), (3,5‐di­chloro­phenyl)­[(Z)‐2‐methyl­but‐1‐en‐1‐yl]­iodo­nium tri­fluoro­methane­sulfonate, C₁₁H₁₂­Cl₂I⁺·CF₃O₃S^?, (II), and bis{[3,5‐bis­(tri­fluoro­methyl)­phenyl][(Z)‐2‐methyl­but‐1‐en‐1‐yl]­iodo­nium} bis­(tri­fluoro­methane­sulfonate) di­chloro­methane solvate, 2C₁₃H₁₂F₆I⁺·­2CF₃­O₃S^?·CH₂Cl₂, (III), are described. Neither simple acyclic β,β‐di­alkyl‐substituted alkenyl­(aryl)­idonium salts nor a series containing electron‐deficient aryl rings have been described prior to this work. Compounds (I)–(III) were found to have distorted square‐planar geometries, with each I atom interacting with two tri­fluoro­methane­sulfonate counter‐ions.     

New palladium complexes with phosphino‐ and phosphinitopyridine ligands

Three new palladium complexes containing a difunctional P,N‐chelate, namely tris­(chloro­{[1‐methyl‐1‐(6‐methyl‐2‐pyridyl)ethoxy]diphenylphospine‐κ²N,P}methyl­palladium(II)chloro­form solvate, 3[Pd(CH₃)Cl(C₂₁H₂₂NOP)]·CHCl₃, (III), dichloro­[2‐(2,6‐dimethyl­phen­yl)‐6‐(diphenyl­phosphinometh­yl)­pyridine‐κ²N,P]palladium(II), [PdCl₂(C₂₆H₂₄NP)], (IV), and chloro­[2‐(2,6‐dimethyl­phen­yl)‐6‐(diphenyl­phos­phino­meth­yl)pyridine‐κ²N,P]methyl­palladium(II), [Pd(CH₃)Cl(C₂₆H₂₄NP)], (V), are reported. Geometric data and the conformations of the ligands around the metal centers, as well as slight distortions of the Pd coordination environments from idealized square‐planar geometry, are discussed and compared with the situations in related compounds. Non‐conventional hydrogen‐bond inter­actions (C—H⋯Cl) have been found in all three complexes. Compound (III) is the first six‐membered chloro–meth­yl–phosphinite P,N‐type Pd^II complex to be structurally characterized.     

A ternary complex of aqua(18‐crown‐6)bis(o‐nitrophenolato)barium(II), the triaqua(18‐crown‐6)(o‐nitrophenolato)barium(II) cation and the o‐nitrophenolate anion

In the title compound [systematic name: tri­aqua(1,4,7,10,13,16‐hexaoxa­cyclo­octa­decane‐κ⁶O)(2‐nitro­phenolato‐κO)­barium(II)–aqua(1,4,7,10,13,16‐hexaoxa­cyclo­octa­decane‐κ⁶O)‐ bis(2‐nitro­phenolato‐κ²O,O′)­barium(II)–2‐nitro­phenolate (1/1/1)], [Ba(C₁₂H₂₄O₆)(C₆H₄NO₃)(H₂O)₃][Ba(C₁₂H₂₄O₆)(C₆H₄NO₃)₂(H₂O)](C₆H₄NO₃), the two Ba^II atoms encapsulated by the 18‐crown‐6 rings have different coordinations. Although both Ba^II atoms are coordinated to the six O atoms of the crowns, in the neutral moiety, the Ba^II atom is coordinated to one terminal O atom from a water mol­ecule, two phenolate O atoms and two nitro‐group O atoms, while in the cationic moiety, the Ba^II atom is coordinated to three terminal O atoms from water mol­ecules and one phenolate O atom. Both the crowns are eclipsed and translated along the b direction. In the asymmetric unit, the three components are interconnected by four O—H?O interactions. The packing is stabilized by two intermolecular C—H?O interactions and by one O—H?O interaction.     

A chloro(2‐pyridinecarboxaldehyde)(2,2′:6′,2′′‐ter­pyridine)­ruthenium(II) complex

The aldehyde moiety in the title complex, chloro(2‐pyridinecarboxaldehyde‐N,O)(2,2′:6′,2′′‐terpyridine‐κ³N)ruthenium(II)–chloro­(2‐pyridine­carboxyl­ic acid‐N,O)(2,2′:6′,2′′‐ter­pyridine‐κ³N)­ruthenium(II)–perchlorate–chloro­form–water (1.8/0.2/2/1/1), [RuCl­(C₆H₅NO)­(C₁₅H₁₁N₃)]_1.8[RuCl­(C₆H₅­NO₂)(C₁₅H₁₁N₃)]_0.2­(ClO₄)₂·­CHCl₃·­H₂O, is a structural model of substrate coordination to a transfer hydrogenation catalyst. The title complex features two independent Ru^II complex cations that display very similar distorted octahedral coordination provided by the three N atoms of the 2,2′:6′,2′′‐ter­pyridine ligand, the N and O atoms of the 2‐pyridine­carbox­aldehyde (pyCHO) ligand and a chloride ligand. One of the cation sites is disordered such that the aldehyde group is replaced by a 20 (1)% contribution from a carboxyl­ic acid group (aldehyde H replaced by carboxyl O—H). Notable dimensions in the non‐disordered complex cation are Ru—N 2.034 (2) Å and Ru—O 2.079 (2) Å to the pyCHO ligand and O—C 1.239 (4) Å for the pyCHO carbonyl group.     

Disappearance of intramolecular stacking due to one‐atom movement or increment of a `propyl­ene linker' in pyrazolo­[3,4‐d]­pyrimidine‐based ­flexible models

In the crystal structures of 4,6‐di­methyl­thio‐1‐[3‐(4,6‐di­methyl­thio‐2H‐pyra­zolo­[3,4‐d]­py­rimi­din‐2‐yl)­propyl]‐1H‐py­ra­­zolo­[3,4‐d]­py­rimi­dine, C₁₇H₂₀N₈S₄, and 1‐[4‐(4‐meth­oxy‐6‐methyl­thio‐1H‐pyra­zolo­[3,4‐d]py­rimi­din‐1‐yl)­butyl]‐5‐meth­yl‐6‐methyl­thio‐4,5‐di­hydro‐1H‐pyra­zolo­[3,4‐d]py­rimi­din‐4‐one, C₁₈H₂₂N₈O₂S₂, only intermolecular stacking due to aromatic π–π interactions between pyrazolo­[3,4‐d]­pyrimidinerings is present.     

catena‐Poly[[[N,N′‐bis­(salicyl­idene)propane‐1,3‐diaminato]cobalt(III)]‐μ‐azido] and catena‐poly[[[N,N′‐bis(salicyl­idene)propane‐1,3‐diaminato]cobalt(III)]‐μ‐thio­cyanato]

The two title complexes, catena‐poly[[{2,2′‐[1,3‐propane­diylbis(nitrilo­methyl­idyne)]diphenolato}cobalt(III)]‐μ‐azido], [Co(C₁₇H₁₆N₂O₂)(N₃)]_n, (I), and catena‐poly[[{2,2′‐[1,3‐propane­diylbis(nitrilo­methyl­idyne)]diphenolato}cobalt(III)]‐μ‐thio­cyanato], [Co(C₁₇H₁₆N₂O₂)(NCS)]_n, (II), are isomorphous polynuclear cobalt(III) compounds. In both structures, the Co^III atom is six‐coordinated in an octa­hedral configuration by two N atoms and two O atoms of one Schiff base, and two terminal N or S atoms from two bridging ligands. The [N,N′‐bis­(salicyl­idene)propane‐1,3‐diaminato]cobalt(III) moieties are linked by the bridging ligands, viz. azide in (I) and thio­cyanate in (II), giving zigzag polymeric chains with backbones of the type [–Co—N—N—N—Co]_n in (I) or [–Co—N—C—S—Co]_n in (II) running along the c axis.     

(η6‐Bi­phenyl)­tri­carbonyl­chromium and μ‐(η6:η6)‐bi­phenyl‐bis­(tricarbonyl­chromium)

The title compounds, [Cr(C₁₂H₁₀)(CO)₃] and [Cr₂(C₁₂H₁₀)(CO)₆], serve as a fundamental standard of comparison for other mono‐ and polysubstituted (η⁶‐bi­phenyl)­tri­carbonyl­chromium compounds. (η⁶‐Bi­phenyl)­tri­carbonyl­chromium has a typical piano‐stool coordination about the Cr center, and the dihedral angle between the planes of the phenyl rings is 23.55 (5)°. The corresponding angle in μ‐(η⁶:η⁶)‐bi­phenyl‐bis­(tri­carbonyl­chromium) is 0° because the mol­ecule occupies a crystallographic inversion center; the Cr atoms reside on opposite sides of the bi­phenyl ligand. Density functional theory and natural bonding orbital theory analyses were used to scrutinize the geometry of these and closely related compounds to explain important structural features.