Different hydrogen‐bonding modes in two closely related oximes

Two closely related oximes, namely 1‐chloroacetyl‐3‐ethyl‐2,6‐diphenylpiperidin‐4‐one oxime, C₂₁H₂₃ClN₂O₂, (I), and 1‐chloroacetyl‐2,6‐diphenyl‐3‐(propan‐2‐yl)piperidin‐4‐one oxime, C₂₂H₂₅ClN₂O₂, (II), despite their identical sets of hydrogen‐bond donors and acceptors, display basically different hydrogen‐bonding patterns in their crystal structures. While the molecules of (I) are organized into typical centrosymmetric dimers, created by oxime–oxime O—H...N hydrogen bonds, in the structure of (II) there are infinite chains of molecules connected by O—H...O hydrogen bonds, in which the carbonyl O atom from the chloroacetyl group acts as the hydrogen‐bond acceptor. Despite the differences in the hydrogen‐bond schemes, the –OH groups are always in typical anti positions (C—N—O—H torsion angles of ca 180°). The oxime group in (I) is disordered, with the hydroxy groups occupying two distinct positions and C—C—N—O torsion angles of approximately 0 and 180° for the two alternatives. This disorder, even though the site‐occupancy factor of the less occupied position is as low as ca 0.06, is also observed at lower temperatures, which seems to favour the statistical and not the dynamic nature of this phenomenon.     

The centrosymmetric dimer of di­chloro­(tri­methyl­siloxy)­aluminium

The title mol­ecule is dimeric, i.e. di‐μ‐tri­methyl­siloxy‐bis­(di­chloro­aluminium), [Al₂Cl₄(C₃H₉Si)₂], and possesses exact crystallographic inversion symmetry. The O atoms of the tri­methyl­siloxy groups bridge the two Al atoms to form a four‐membered ring. The Si—O bond distance [1.711 (3) Å], the Al—O mean bond distance [1.806 (4) Å] and the mean Si—C bond distance [1.875 (6) Å] appear to agree well with standard data. Mean values for C—Si—C, O—Si—C, and Si—O—Al angles are 112.9 (3), 105.8 (2), and 131.8 (2)° repectively. The two ring angles O—Al—O and Al—O—Al are 84.43 (16) and 95.57 (16)°, respectively.     

A pyrazine bis‐adduct of a binuclear rhodium(II) carboxylate containing 3,4,5‐triethoxybenzoate as the ­equatorial ligand

The title compound, tetrakis(μ‐3,4,5‐triethoxy­benzoato‐κ²O:O′)­bis­[(pyrazine‐κN)­rhodium(II)](Rh—Rh), [Rh₂(C₁₃H₁₇O₅)₄(C₄H₄N₂)₂], crystallizes on an inversion centre in the triclinic space group . The equatorial carboxyl­ate ligands bridge the two Rh^II atoms, giving a binuclear lantern‐like structure. The pyrazine mol­ecules occupy the two axial coordination sites. The phenyl rings are tilted by ca 10° with respect to the attached carboxyl­ate groups. The pyrazine planes have a torsion angle of ca 19° around the Rh—N bond with respect to the plane of the nearer carboxyl­ate group and are not coplanar with the Rh—Rh bond.     

Crystal‐to‐crystal transformation upon dehydration of a copper(II) 2,2′:6′,2′′‐terpyridine complex

The reaction of 2,2′:6′,2′′‐terpyridine (terpy) with CuCl₂ in the presence of sodium sulfite led to the synthesis of the ionic complex aquachlorido(2,2′:6′,2′′‐terpyridyl‐κ³N,N′,N′′)copper(II) chlorido(dithionato‐κO)(2,2′:6′,2′′‐terpyridyl‐κ³N,N′,N′′)cuprate(II) dihydrate, [CuCl(C₁₅H₁₁N₃)(H₂O)][CuCl(S₂O₆)(C₁₅H₁₁N₃)]·2H₂O, (I), and the in situ synthesis of the S₂O₆²⁻ dianion. Compound (I) is composed of a [CuCl(terpy)(H₂O)]⁺ cation, a [Cu(S₂O₆)(terpy)]⁻ anion and two solvent water molecules. Thermogravimetric analysis indicated the loss of two water molecules at ca 363 K, and at 433 K the weight loss indicated a total loss of 2.5 water molecules. The crystal structure analysis of the resulting pale‐green dried crystals, μ‐dithionato‐κ²O:O′‐bis[chlorido(2,2′:6′,2′′‐terpyridyl‐κ³N,N′,N′′)copper(II)] monohydrate, [Cu₂Cl₂(S₂O₆)(C₁₅H₁₁N₃)₂]·H₂O, (II), revealed a net loss of 1.5 water molecules and the formation of a binuclear complex with two [CuCl(terpy)]⁺ cations bridged by a dithionate dianion. The crystal‐to‐crystal transformation involved an effective reduction in the unit‐cell volume of ca 7.6%. In (I), the ions are linked by O—H...O hydrogen bonds involving the coordinated and solvent water molecules and O atoms of the dithionate unit, to form ribbon‐like polymer chains propagating in [100]. These chains are linked by Cu...Cl interactions [3.2626 (7) Å in the cation and 3.3492 (7) Å in the anion] centred about inversion centres, to form two‐dimensional networks lying in and parallel to (01). In (II), symmetry‐related molecules are linked by O—H...O hydrogen bonds involving the partially occupied disordered water molecule and an O atom of the bridging thiosulfite anion, to form ribbon‐like polymer chains propagating in [100]. These chains are also linked by Cu...Cl interactions [3.3765 (12) Å] centred about inversion centres to form similar two‐dimensional networks to (I) lying in and parallel to (02), crosslinked into three dimensions by C—H...O=S and C—H...O(water) interactions.     

Comparison of two polymeric transition metal complexes with 1,4‐benzenedicarboxylate ions as bridging ligands, [Co(C8H4O4)(C12H8N2)(H2O)] and [Cu(C8H4O4)(C10H9N3)]·H2O

The title complexes, catena‐poly[[aqua(1,10‐phenanthroline‐κ²N,N′)­cobalt(II)]‐μ‐benzene‐1,4‐di­carboxyl­ato‐κ²O¹:O⁴], [Co(C₈H₄O₄)(C₁₂H₈N₂)(H₂O)], (I), and catena‐poly[[[(di‐2‐pyridyl‐κN‐amine)copper(II)]‐μ‐benzene‐1,4‐di­carboxyl­ato‐κ⁴O¹,O^1′:O⁴,O^4′] hydrate], [Cu(C₈H₄O₄)(C₁₀H₉N₃)]·H₂O, (II), take the form of zigzag chains, with the 1,4‐benzene­di­carboxyl­ate ion acting as an amphimonodentate ligand in (I) and a bis‐bidentate ligand in (II). The Co^II ion in (I) is five‐coordinate and has a distorted trigonal–bipyramidal geometry. The Cu^II ion in (II) is in a very distorted octahedral 4+2 environment, with the octahedron elongated along the trans O—Cu—O bonds and with a trans O—Cu—O angle of only 137.22 (8)°.     

Hydro­gen bonds and C—H⋯O interactions in 2,2′‐dimethoxybiphenyl‐5,5′‐dimethanol at 150 K

The title compound, C₁₆H₁₈O₄, crystallized in the centrosymmetric space group P2₁/c with one mol­ecule in the asymmetric unit. The two hydroxyl‐H atoms are ordered, and are involved in intermolecular hydrogen bonds with O_donor?O_acceptor distances of 2.761 (1) and 2.699 (1) Å, and O—H?O angles of 157 (2) and 168 (2)°. Seven leading intermolecular C—H?O interactions have H?O distances ranging from 2.41 to 2.76 Å and C—H?O angles ranging from 125 to 170°. The hydrogen bonds and C—H?O interactions form chain and ring patterns, resulting in a richly three‐dimensional network. The bi­phenyl twist angle is 67.2 (1)°.     

Tris­[(R)‐lact­amide‐κ2O,O′]­zinc(II) tetra­bromo­zincate

The title compound, tris­[(R)‐2‐hydroxy­propan­amide‐κ²O,O′]­zinc(II) tetra­bromo­zincate, [Zn(C₃H₇NO₂)₃][ZnBr₄], contains one monomeric six‐coordinate zinc complex cation and one tetrahedral [ZnBr₄]²⁻ anion. Both Zn^II atoms lie on threefold axes. Coordination in the cation occurs via the amide and hydroxy O atoms [Zn—O = 2.074 (5) and 2.073 (6) Å] and has a distorted octahedral geometry, with cis‐O—Zn—O angles in the range 76.2 (2)–109.2 (2)°. In the crystal structure, the cations and anions are linked by N—H⋯Br and O—H⋯O hydrogen bonds, generating a three‐dimensional network.     

Poly­sulfonyl­amines. CXLV.

The prominent features in the molecular structure of the title compound (alternative name: 2‐diethyl­carbamoyl‐1,1,3,3‐tetraoxo‐1,3,2‐benzodi­thia­zole), C₁₁H₁₄N₂O₅S₂, arise in the urea moiety S₂N—C(O)—N′C₂: the sum of the angles at N is 332.3 (1)°, the N—C(O)—N′C₂ unit is planar, and distances N—C(O) = 1.494 (3) Å, N′—C(O) = 1.325 (2) Å and C—O = 1.215 (2) Å. The mol­ecules are associated via five C—H?O hydrogen bonds to form layers parallel to the yz plane. This compound and its di­methyl homologue, which were synthesized by treating the silver salt of o‐benzene­disulfon­imide with carbamoyl chlorides, are prone to rapid hydro­lysis at the weak N—C(O) bond. For both mol­ecules, the rotational barrier about the partial N′—C(O) double bond is ca 50 kJ mol^?1 at 250 K (from dynamic ¹H NMR experiments).     

The polyoctahedral silsesquioxane (POSS) 1,3,5,7,9,11,13,15‐octaphenylpentacyclo[9.5.1.13,9.15,15.17,13]octasiloxane (octaphenyl‐POSS)

Solvent‐free single crystals of 1,3,5,7,9,11,13,15‐octaphenylpentacyclo[9.5.1.1^3,9.1^5,15.1^7,13]octasiloxane (abbreviated as octaphenyl‐POSS), C₄₈H₄₀O₁₂Si₈, were obtained by dehydration/condensation of the tetrol Si₄O₄(Ph)₄(OH)₄. The powder pattern generated from the single‐crystal data matches well with the experimentally measured powder pattern of commercial octaphenyl‐POSS. The geometry of the centrosymmetric molecule in the crystal was compared with that in the gas phase, and had shorter Si—O bond lengths and a broader range of Si—O—Si bond angles. The average Si—O bond length [1.621 (3) Å], and Si—O—Si and O—Si—O bond angles [149 (5) and 109 (1)°, respectively] were within the same range measured previously for octaphenyl‐POSS solvates.     

Adducts of nickel(II) acetylacetonate chelating with heterocyclic bases: 3‐­cyanopyridine and 4‐cyanopyridine

In both title compounds, (acetyl­acetonato‐O,O′)­bis(3‐cyano­pyridine‐N)­nickel(II), (I), and (acetyl­acetonato‐O,O′)­bis(4‐cyanopyridine‐N)­nickel(II), (II), both [Ni(C₅­H₇O₂)₂(C₆H₄N₂)₂], the Ni^II atom, which is situated on a centre of symmetry, is octahedrally coordinated. Distances and angles for (I) and (II), respectively, are: Ni—O 2.009 (2)/2.016 (2) and 2.0110 (16)/2.0238 (18) Å, Ni—N 2.116 (3) and 2.179 (2) Å, O—Ni—O 91.86 (10) and 90.19 (7)°, and O—Ni—N 91.27 (11)/90.19 (11) and 89.65 (8)/90.79 (7)°.     

Aqua(dipicolinato‐κ3O2,N,O6)(1,10‐phenanthroline‐κ2N,N′)manganese(II) monohydrate

In the title compound [systematic name: aqua(1,10‐phenanthroline‐κ²N,N′)(pyridine‐2,6‐di­carboxyl­ato‐κ³O²,N,O⁶)manganese(II) monohydrate, [Mn(C₇H₃NO₄)(C₁₂H₈N₂)(H₂O)]·H₂O, the manganese(II) centre is surrounded by one bidentate phenanthroline ligand [Mn—N = 2.248 (3) and 2.278 (3) Å], one tridentate dipicolinate ligand [Mn—N = 2.179 (3) Å, and Mn—O = 2.237 (2) and 2.266 (2) Å] and one water mol­ecule [Mn—O = 2.117 (3) Å], and it exhibits a strongly distorted octahedral geometry, with trans angles ranging from 144.12 (9) to 158.88 (11)°. Extensive intermolecular hydrogen‐bonding interactions involving coordinated and uncoordinated water mol­ecules and the carboxyl O atoms of the dipicolinate ligand, as well as a stacking interaction involving the phenanthroline rings, are observed in the crystal structure.     

cis‐Bis(3,6‐di­hydro‐2H‐1,2‐oxazine‐N)­di­iodo­platinum(II) and cis‐bis(3,4,5,6‐tetra­hydro‐2H‐1,2‐oxazine‐N)­di­iodo­platinum(II)

The title complexes, [Pt(C₄H₇NO)₂I₂], (I), and [Pt(C₄H₉NO)₂I₂], (II), possess similar square‐planar coordination geometries with modest distortions from ideality. For (I), the cis‐L—Pt—L angles are in the range 87.0 (4)–94.2 (3)°, while the trans angles are 174.4 (3) and 176.4 (3)°. For (II), cis‐L—Pt—L are 86.1 (8)–94.2 (6)° and trans‐L—Pt—L are 174.4 (6) and 177.4 (5)°. One 3,6‐di­hydro‐2H‐1,2‐oxazine ligand in (I) is rotated so that the N—O bond is out of the square plane by approximately 70°, while the N—C bond is only ca 20° out of the plane. The other oxazine ligand is rotated so that the N—C bond is about 80° out of the plane, while the N—O bond is out of the plane by approximately 24°. In (II), the 3,4,5,6‐tetra­hydro‐2H‐1,2‐oxazine ligands are also positioned with one having the N—O bond further out of the plane and the other having the N—C bond positioned in that fashion. Both ligands, however, are rotated approximately 90° compared with their positions in (I). In both complexes, this results in an unsymmetrical distortion of the I—Pt—N bond angles in which one is expanded and the other contracted. These features are compared to those of reported cis‐di­amine­di­iodo­platinum(II) complexes.     

Cadmium nitrate coordination polymers with substituted pyridazino[4,5‐d]pyridazines

catena‐Poly[[aquabis(nitrato‐κ²O,O′)cadmium(II)]‐μ‐1,2,3,6,7,8‐hexa­hydro­cinnolino[5,4,3‐cde]cinnoline‐κN¹:κN⁶], [Cd(NO₃)₂(C₁₂H₁₂N₄)(H₂O)]_n, (I), and catena‐poly[[[bis(nitrato‐κ²O,O′)cadmium(II)]‐μ‐2,2,7,7‐tetra­methyl‐1,2,3,6,7,8‐hexahydro­cinnolino[5,4,3‐cde]cinnoline‐κN¹:κN⁶] chloro­form solvate], {[Cd(NO₃)₂(C₁₂H₁₂N₄)]·CHCl₃}_n, (II), are the first structurally examined cadmium–pyridazine coordination compounds. They possess one‐dimensional polymeric structures supported by the bidentate bridging function of the cinnolino[5,4,3‐cde]cinnoline ligands, which lie about inversion centres. The Cd atoms are seven‐coordinated in (I) and six‐coordinated in (II), involving two bidentate nitrate groups [Cd—O = 2.229 (2)–2.657 (2) Å], two N atoms of the cinnoline ligands [Cd—N = 2.252 (2)–2.425 (2) Å], and, additionally, a water O atom in (I) [Cd—O = 2.284 (2) Å]. In (I), the coordinated organic and aqua ligands form an intra­molecular O—H⋯N hydrogen bond [O⋯N = 2.730 (3) Å].     

Structural comparison of group 7 tricarbonyl complexes of 2‐{[2‐(1H‐imidazol‐4‐yl)ethyl]iminomethyl}‐5‐methylphenolate

Two tricarbonyl complexes of rhenium(I) and manganese(I) coordinated by the ligand 2‐{[2‐(1H‐imidazol‐4‐yl)ethyl]iminomethyl}‐5‐methylphenolate are reported, viz. fac‐tricarbonyl(2‐{[2‐(1H‐imidazol‐4‐yl‐κN³)ethyl]iminomethyl‐κN}‐5‐methylphenolato‐κO)rhenium(I) methanol monosolvate, [Re(C₁₆H₁₄N₃O₄)(CO)₃]·CH₃OH, (I), and fac‐tricarbonyl(2‐{[2‐(1H‐imidazol‐4‐yl‐κN³)ethyl]iminomethyl‐κN}‐5‐methylphenolato‐κO)manganese(I), fac‐[Mn(C₁₆H₁₄N₃O₄)(CO)₃], (II), display facial coordination in a distorted octahedral environment. The crystal structure of (I) is stabilized by O—H...O, N—H...O and C—H...O hydrogen‐bond interactions, while that of (II) is stabilized by N—H...O hydrogen‐bond interactions only. These interactions result in two‐dimensional networks and π–π stacking for both structures.     

1‐Methyl‐4‐nitraminopyridinium nitrate and 4‐nitraminopyridinium methanesulfonate

In the title compounds, C₆H₈N₃O₂⁺·NO₃^? and C₅­H₆­N₃­O₂⁺·­CH₃SO₃^?, respectively, the cations are almost planar; the twist of the nitr­amino group about the C—N and N—N bonds does not exceed 10°. The deviations from coplanarity are accounted for by intermolecular N—H?O interactions. The coplanarity of the NHNO₂ group and the phenyl ring leads to the deformation of the nitr­amino group. The C—N—N angle and one C—C—N angle at the junction of the phenyl ring and the nitr­amino group are increased from 120° by ca 6°, whereas the other junction C—C—N angle is decreased by ca 5°. Within the nitro group, the O—N—O angle is increased by ca 5° and one O—N—N angle is decreased by ca 5°, whereas the other O—N—N angle remains almost unchanged. The cations are connected to the anions by relatively strong N—H?O hydrogen bonds [shortest H?O separations 1.77 (2)–1.81 (3) Å] and much weaker C—H?O hydrogen bonds [H?O separations 2.30 (2)–2.63 (3) Å].     

Adducts of bis(acetylacetonato)zinc(II) with 1,10‐phenanthroline and 2,2′‐bipyridine

In each of the zinc(II) complexes bis(acetylacetonato‐κ²O,O′)(1,10‐phenanthroline‐κ²N,N′)zinc(II), [Zn(C₅H₇O₂)₂(C₁₂H₈N₂)], (I), and bis(acetylacetonato‐κ²O,O′)(2,2′‐bipyridine‐κ²N,N′)zinc(II), [Zn(C₅H₇O₂)₂(C₁₀H₈N₂)], (II), the metal center has a distorted octahedral coordination geometry. Compound (I) has crystallographically imposed twofold symmetry, with Z′ = 0.5. The presence of a rigid phenanthroline group precludes intramolecular hydrogen bonding, whereas the rather flexible bipyridyl ligand is twisted to form an intramolecular C—H...O interaction [the chelated bipyridyl ligand is nonplanar, with the pyridyl rings inclined at an angle of 13.4 (1)°]. The two metal complexes are linked by dissimilar C—H...O interactions into one‐dimensional chains. The present study demonstrates the distinct effects of two commonly used ligands, viz. 1,10‐phenanthroline and 2,2′‐bipyridine, on the structures of metal complexes and their assembly.     

Hydro­gen bonds and C—H⃛O interactions in N‐(2‐hydroxy‐1,1‐dimethyl­ethyl)benzamide at 150 K

The title compound, C₁₁H₁₅NO₂, crystallized in the centrosymmetric space group P2₁/n with one mol­ecule in the asymmetric unit. There is a single intermolecular hydrogen bond, in which the N_donor?O_acceptor distance is 3.0374 (11) Å and the N—H?O angle is 171.0 (12)°. The single intramol­ecular hydrogen bond has an O_donor?O_acceptor distance of 2.6279 (11) Å and an O—H?O angle of 161.8 (14)°. The four leading intermolecular C—H?O interactions have H?O distances ranging from 2.52 to 2.65 (2) Å and C—H?O angles ranging from 125.2 (9) to 143°. Chains of interactions form two‐dimensional networks.     

S‐(4‐Nitrophenyl) 4‐nitrobenzenethiosulfonate

The title compound, C₁₂H₈N₂O₆S₂, (I), is a positional isomer of S‐(2‐nitrophenyl) 2‐nitrobenzenethiosulfonate [Glidewell, Low & Wardell (2000). Acta Cryst. B 56 , 893–905], (II). The most obvious difference between the two isomers is the rotation of the nitro groups with respect to the planes of the adjacent aryl rings. In (I), the nitro groups are only slightly rotated out of the plane of the adjacent aryl ring [2.4 (6) and 6.7 (7)°], while in (II) the nitro groups are rotated by between 37 and 52°, in every case associated with S—S—C—C torsion angles close to 90°. Other important differences between the isomers are the C—S—S(O₂)—C torsion angle [78.39 (2)° for (I) and 69.8 (3)° for (II) (mean)] and the dihedral angles between the aromatic rings [12.3 (3)° for (I) and 28.6 (3)° for (II) (mean)]. There are two types of C—H...O hydrogen bond in the structure [C...O = 3.262 (7) Å and C—H...O = 144°; C...O = 3.447 (7) Å and C—H...O = 166°] and these link the molecules into a two‐dimensional framework. The hydrogen‐bond‐acceptor properties differ between the two isomers.     

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.     

Solvated and solvent‐free forms of N,N′‐di­thio­diphthal­imide

N,N′‐Di­thio­diphthal­imide, C₁₆H₈N₂O₄S₂, crystallizes from ethyl acetate with two independent mol­ecules in the asymmetric unit, in which the N—S—S—N torsion angles are ?83.59 (19) and 92.9 (2)°. The mol­ecules are linked by C—H?O hydrogen bonds and aromatic π–π‐stacking interactions into a three‐dimensional framework. When crystallized from either di­chloro­methane or ethanol, solvates are formed in which the mol­ecules of the title compound lie across twofold rotation axes in space group C2/c, with N—S—S—N torsion angles of 93.54 (7) and 96.14 (11)°. There are no hydrogen bonds in these solvates, but the mol­ecules are linked by aromatic π–π‐stacking interactions into chains, between which there are continuous channels. Disordered solvent mol­ecules occupy these channels, which account for ca 20% of the unit‐cell volume.