cis,cis,cis‐1,2,4,5‐Cyclo­hexane­tetra­carboxyl­ic acid and its dianhydride

cis,cis,cis‐1,2,4,5‐Cyclo­hexane­tetra­carboxyl­ic acid, C₁₀H₁₂O₈, (I), contains a mirror plane and the cyclo­hexane ring exhibits a chair conformation. Two crystallographically independent hydrogen bonds form (14), (16) and (16) ring motifs, and propagation of these two hydrogen bonds along the c and b axes generates (16) and (7) chains. cis,cis,cis‐1,2:4,5‐Cyclo­hexane­tetra­carboxyl­ic dianhydride, C₁₀H₈O₆, (II), was prepared by the reaction of (I) with acetic anhydride. The cyclo­hexane ring of (II) exhibits a boat conformation and the dihedral angle between the two an­hydro rings is 117.5 (1)°.     

Di‐μ‐hydro­xo‐bis­(diiso­propyl­gallium)–1,4,8,11‐tetra­methyl‐1,4,8,11‐tetra­aza­cyclo­tetra­decane (1/1)

The hydro­lysis product [Ga₂(C₃H₇)₄(OH)₂]·C₁₄H₃₂N₄, derived from the tetrakis­(triiso­propyl­gallium)–1,4,8,11‐tetra­methyl‐1,4,8,11‐tetra­aza­cyclo­tetra­decane (1/1) adduct, consists of a centrosymmetric [ⁱPr₂Ga(μ‐OH)]₂ unit hydrogen bonded through the hydroxyl group to a nitro­gen on an adjacent centrosymmetric 1,4,8,11‐tetra­methyl‐1,4,8,11‐tetra­aza­cyclo­tetra­decane molecule, resulting in the generation of a molecular chain through the crystal.     

A dinuclear uranium(IV) complex of the chelating ligand 1,2,3,4‐tetra­methyl‐5‐(2‐pyridyl)­cyclo­penta­diene

The ligand 1,2,3,4‐tetra­methyl‐5‐(2‐pyridyl)­cyclo­penta­diene (cp*py) forms a dinuclear complex with U^IV, i.e. di‐μ‐oxo‐bis­{chloro­(diethyl ether‐κO)[(η⁵,κN)‐1,2,3,4‐tetra­methyl‐5‐(2‐pyridyl)­cyclo­penta­dienyl]uranium(IV)}, [U₂Cl₂O₂(C₁₄H₁₆N)₂(C₄H₁₀O)₂], in which cp*py acts as a chelating ligand, being bound to the metal atom by the cyclo­penta­dienyl unit and also by the N atom of the pyridyl ring.     

Four bis(1‐chloro‐2,2,4,4‐tetramethyl‐3‐oxocyclobutan‐1‐yl)oligosulfanes

The four oligosulfanes, bis(1‐chloro‐2,2,4,4‐tetra­methyl‐3‐oxo­cyclo­butan‐1‐yl)­disulfane, C₁₆H₂₄Cl₂O₂S₂, (III), 1,3‐bis(1‐chloro‐2,2,4,4‐tetra­methyl‐3‐oxo­cyclo­butan‐1‐yl)­trisulfane, C₁₆H₂₄Cl₂O₂S₃, (V), 1,4‐bis(1‐chloro‐2,2,4,4‐tetra­methyl‐3‐oxo­cyclo­butan‐1‐yl)­tetrasulfane, C₁₆H₂₄Cl₂O₂S₄, (VII), and 1,6‐bis(1‐chloro‐2,2,4,4‐tetra­methyl‐3‐oxo­cyclo­butan‐1‐yl)­hexasul­fane, C₁₆H₂₄Cl₂O₂S₆, (VIII), all have similar geometric parameters, with the C—C bond lengths involving the chloro‐substituted cyclo­butanyl C atom being elongated to about 1.59 Å. There are two mol­ecules in the asymmetric units of the tri‐ and tetrasulfanes, and the mol­ecules in the latter compound have local C₂ symmetry. The mol­ecule of the hexasulfane has crystallographic C₂ symmetry. Most of the cyclo­butanyl rings are not perfectly planar and have slight but varying degrees of distortion towards a flattened tetrahedron. The polysulfane chain in each structure has a helical conformation, with each additional S atom in the chain adding approximately one quarter of a turn to the helix.     

NiII and ZnII complexes of the hexadentate macrocyclic ligand cis‐6,13‐di­methyl‐1,4,8,11‐tetra­aza­cyclo­tetra­decane‐6,13‐di­amine

The title pendent‐arm macrocyclic hexa­amine ligand binds stereospecifically in a hexadentate manner, and we report here its isomorphous Ni^II and Zn^II complexes (both as perchlorate salts), namely (cis‐6,13‐di­methyl‐1,4,8,11‐tetra­aza­cyclo­tetra­decane‐6,13‐di­amine‐κ⁶N)­nickel(II) di­per­chlorate, [Ni(C₁₂H₃₀N₆)]­­(ClO₄)₂, and (cis‐6,13‐di­methyl‐1,4,8,11‐tetraaza‐cyclo­tetra­decane‐6,13‐di­amine‐κ⁶N)­zinc(II) di­per­chlorate, [Zn(C₁₂H₃₀N₆)]­(ClO₄)₂. Distortion of the N—M—N valence angles from their ideal octahedral values becomes more pronounced with increasing metal‐ion size and the present results are compared with other structures of this ligand.     

Di­spiro­[fluorene‐9,5′‐[1,2,3,4]­tetra­thia­ne‐6′,9′′‐fluorene]

The tetra­thia­ne ring of the title compound, C₂₆H₁₆S₄, has a chair conformation and the mol­ecule has approximate C₂ symmetry. Each of the two fluorene ring systems is virtually planar, with the ring planes intersecting at an angle of 67.58 (5)°. This novel compound has been formed as a side product from the treatment of 9H‐fluorene‐9‐thione with methyl N‐[(benzyl­idene)­phenyl]­glycinate in the presence of LiBr and 1,6‐di­aza­bi­cyclo­[5.4.0]­un­decane.     

(1R*,2R*)‐1,2‐(2,3‐Di­methoxy­butane‐2,3‐dioxy)cyclo­hexane

The title compound, 2,3‐di­methoxy‐2,3‐di­methyl‐5,6,7,8‐tetra­hydro‐4‐oxa­chroman, C₁₂H₂₂O₄, was synthesized as a model compound for substituted diequatorial fixed vicinal trans‐cyclo­hexane­diols.     

1,3‐Bridged p‐methyloctahomotetraoxacalix[4]arene–bis‐crown‐3

The title compound, 13,21,35,43‐tetra­methyl‐3,6,9,17,25,28,31,39,46,49‐decaoxahepta­cyclo­[21.21.3.3^11,33.0^2,41.0^10,15.0^19,24.0^32,37]pentaconta‐1,10,12,14,19,21,23,32,34,36,41,43‐dodecaene, C₄₄H₅₂O₁₀, differs from previously reported 1,3‐bridged calix­[4]­arene–bis‐crown compounds in having an enlarged calixarene ring and shorter polyoxy­ethyl­ene bridges. The cavity is partly filled by the bridges.     

1,2,4‐Triazolo­[2,3‐h]‐7,9‐thi­aza‐11‐crown‐4

The title compound, 4,7‐dioxa‐10‐thia‐1,12,13‐tri­aza­bi­cyclo­[9.3.0]­tetra­deca‐11,13‐diene, C₈H₁₃N₃O₂S, contains an 11‐membered ring, which appears in a chair conformation and has approximate mirror symmetry. It may be used for the complexation of metal atoms.     

4,5,9,10‐Tetrahydro‐4‐methyl‐2‐phenyl‐9,10‐epoxy‐3H,10aH‐cyclobuta[a]benzo[2,3,4‐de]isoquinoline‐3,5‐dione

In the title compound, C₂₁H₁₅NO₃, which is one of the photoreaction products of N‐methyl‐1,8‐naphthalene­dicar­box­imide with phenyl­acetyl­ene, the cyclo­butene and epoxy rings are trans to each other across the cyclo­hexene ring of the tetralin moiety. The dihedral angle between the mean planes of the cyclo­butene and cyclo­hexene rings is 112.80 (2)°, while the latter makes a dihedral angle of 103.70 (9)° with the epoxy ring. The crystal structure is stabilized by C—H⋯O intermolecular interactions.     

Methoxy‐ether and crown‐ether ­derivatives of tetrahomodioxa‐ and octahomotetraoxacalix­[4]­arenes

Three methoxy­‐ether and one methoxy‐­ether/crown‐ether derivatives of p‐tert‐butyl­tetrahomodioxa‐ and p‐R‐octahomo­tetraoxacalix­[4]­arenes (R = methyl, tert‐butyl, H) have been investigated. The first three compounds, 7,15,21,27‐tetra‐tert‐butyl‐29,30,31,32‐tetra­methoxy‐3,11‐dioxapenta­cyclo­[23.3.­1.1^5,9.1^13,17.1^19,23]­ditriaconta‐1(29),5,7,­9(30),­13,15,‐17(31),­19,21,23(32),25,27‐dodecaene, C₅₀H₆₈O₆, 33,34,35,36‐tetra­methoxy‐7,15,23,31‐tetra­methyl‐3,11,19,27‐tetra­oxa­penta­cyclo[27.3.1.1^5,9.1^13,17.1^21,25]­hexa­tri­aconta‐1(33),5,7,9(34),13,15,­17(35),21,23,25(36),29,31‐dodecaene, C₄₀H₄₈O₈, and 7,23‐di‐tert‐butyl‐33,34,35,36‐tetra­methoxy‐3,11,19,27‐tetraoxapenta­cyclo­[27.3.1.1^5,9.1^13,17.1^21,25]­hexatriaconta‐1(33),5,7,9(34),13,15,­17(35),‐ 21,23,25(36),29,31‐dodecaene, C₄₄H₅₆O₈, in the partial‐cone or 1,2‐alternate conformations, present the common feature of methoxy‐­ether self‐inclusion, while the fourth, 42,43‐di­methoxy‐7,15,23,31‐tetra­methyl‐3,11,19,27,34,37,40‐heptaoxahexa­cyclo[15.15.9.1^5,9.1^21,25.0^13,41.0^29,33]­tritetra­conta‐5(42),6,8,13(41),­14,16,21(43),22,24,29(33),30,32‐dodecaene, C₄₂H₅₀O₉, adopts the 1,3‐alternate conformation owing to the presence of a 1,3‐polyether chain.     

X‐ray investigations of bicyclic α‐methyl­ene‐δ‐valerolactones. II. (4aS,8aS)‐4a‐Methyl‐3‐methyl­eneper­hydro­chromen‐2‐one

The title compound, C₁₁H₁₆O₂, adopts a semifolded conformation with the δ‐lactone and cyclo­hexane rings almost perpendicular to one another. The β‐methyl substituent occupies an axial position with respect to the cyclo­hexane ring. The δ‐lactone moiety adopts a slightly distorted half‐chair arrangement, while the cyclo­hexane ring exists in an almost ideal chair conformation.     

(4R,4aR,6S,7S,7aS)‐6‐Hydro­xy‐7‐hy­droxy­methyl‐4‐methyl­per­hydro­cyclo­penta­[c]­pyran‐1‐one chloro­form solvate from Valeriana laxiflora

The structure of an iridolactone isolated from Valeriana laxiflora was established as (4R,4aR,6S,7S,7aS)‐6‐hydroxy‐7‐hydroxy­methyl‐4‐methyl­per­hydro­cyclo­penta­[c]­pyran‐1‐one chloro­form solvate, C₁₀H₁₆O₄·CHCl₃. The two rings are cis‐fused. The δ‐lactone ring adopts a slightly twisted half‐chair conformation with approximate planarity of the lactone group and the cyclo­pentane ring adopts an envelope conformation. The hydroxy group, the hydroxymethyl group and the methyl group all have β orientations. The absolute configuration was determined using anomalous dispersion data enhanced by the adventitious inclusion of a chloro­form solvent mol­ecule. Hydro­gen bonding, crystal packing and ring conformations are discussed in detail.     

The monoclinic polymorph of rac‐5,7,7,12,12,14‐hexa­methyl‐1,4,8,11‐tetraazonia­cyclo­tetra­decane bis­(hexa­fluoro­germanate) tetrahydrate

X‐ray data were obtained for the monoclinic polymorph of rac‐5,7,7,12,12,14‐hexa­methyl‐1,4,8,11‐tetraazonia­cyclo­tetra­decane bis­(hexa­fluoro­germanate) tetrahydrate, (C₁₆H₄₀N₄)[GeF₆]₂·4H₂O. The tetra­aza‐macrocyclic cations lie across inversion centers in space group P2₁/c. Water mol­ecules and [GeF₆]²⁻ anions form zigzag chains, which alternate in a three‐dimensional network with the macrocyclic cations. The structure is sustained by multiple hydrogen bonds.     

[(1,4,8,11‐Tetraazacyclotetradeca‐1,4,8,11‐tetrayl)tetraacetamide‐κ6N1,N4,N8,N11,O1,O8]copper(II) sulfate 4.5‐hydrate

The crystal structure of the title copper(II) complex, [Cu(C₁₈H₃₆N₈O₄)]SO₄·4.5H₂O, formed with the tetra­amide cyclam derivative 2‐(4,8,11‐triscarbamoyl­methyl‐1,4,8,11‐tetra­aza­cyclo­tetradec‐1‐yl)­acet­amide (TETAM), is described. The macrocycle lies on an inversion centre occupied by the hexacoordinated Cu atom. The four macrocyclic tertiary amines form the equatorial plane of an axially Jahn–Teller elongated octahedron. Two O atoms belonging to two diagonally opposite amide groups occupy the apical positions, giving rise to a trans‐III stereochemistry, while both the remaining pendant side arms extend outwards from the macrocyclic cavity and are engaged in hydrogen bonds with sulfate anions and co‐crystallized water mol­ecules.     

2‐(6‐Bromo­pyridin‐2‐yl)‐6‐methyl‐[1,3,6,2]­diox­aza­borocane,a new stable (pyridin‐2‐yl)­boronic acid derivative

The crystal structure of the first reported non‐substituted N‐methyl­diox­aza­borocane confirms that the presence of a methyl group attached to the N atom introduces an NB bond length that is longer than that in a simple diox­aza­borocane ring. The presence of more N atoms in the vicinity of the B atom in the title compound [systematic name: 6a‐(6‐bromo­pyridin‐2‐yl)‐3a‐methyl‐2,3,4,5‐tetra­hydro‐1,6‐dioxa‐3a‐aza‐6a‐borapentalene], C₁₀H₁₄BBrN₂O₂, does not modify significantly any structural parameter in the diox­aza­borocane ring. On the other hand, a small asymmetry appears in the bond angles of the pyridine C atom next to the B atom.     

Tetra­allyl (2,2′‐bipyridyl)‐rac‐3,3,7,7‐tetra­methyl‐trans‐5‐palladatricyclo[4.1.0.02,4]­heptane‐1,2,4,6‐tetra­carboxyl­ate above and below the phase‐transition temperature of 194 K

The crystal structure of the title compound, (2,2′‐bipyridyl‐κ²N,N′)(tetra­allyl 3,3,3′,3′‐tetra­methyl‐1,1′‐bi­cyclo­propane‐1,1′,2,2′‐tetra­carboxyl­ato‐κ²C²,C^2′)­palladium(II), [Pd(C₂₆H₃₂­O₈)(C₁₀­H₈­N₂)], is disordered above 194 K. A doubling of the unit cell is observed on cooling. The structure at 143 K contains two ordered mol­ecules related by a pseudo‐translation vector of approximately (0.44,0.00,0.50) or a pseudo‐inversion center at approximately (0.22,0.00,0.25). Weak intermolecular C—H?O interactions are enhanced in the low‐temperature structure.     

Di­methyl 6‐methoxy‐4aβ‐methyl‐9‐oxo‐1,2,3,4,4a,9,10,10aβ‐octa­hydro­phenanthrene‐1,1‐di­carboxyl­ate

In the title tricyclic keto‐diester, C₂₀H₂₄O₆, a potential intermediate in the synthesis of bioactive podocarpic acid, the outer cyclo­hexane ring (in a chair conformation) is cis fused to the central cyclo­hexanone ring (in a half‐chair conformation). The conformational analysis of the compound, investigated by semi‐empirical quantum mechanical AM1 calculations, shows a good agreement with the X‐ray structure, except for the orientation of the methyl, methoxy­phenyl and methoxy­carbonyl substituents.     

5,7,7,12,14,14‐Hexamethyl‐4,11‐diaza‐1,8‐diazonia­cyclo­tetra­decane penta­cyano­nitroso­ferrate(II) dihydrate: a supramolecular compound constructed by hydrogen bonds

The title compound, (C₁₆H₃₈N₄)[Fe(CN)₅(NO)]·2H₂O, contains one [Fe(CN)₅(NO)]²⁻ dianion, two half [H₂teta]²⁺ dications (teta is 5,7,7,12,14,14‐hexa­methyl‐1,4,8,11‐tetra­aza­cyclo­tetra­decane), each lying about an independent inversion centre, and two solvent water mol­ecules, all of which are held together by hydrogen bonds to form a three‐dimensional supramolecular framework.     

Packing considerations of bis‐dimedone derivatives

We have determined the crystal structures of 2,2′‐(4‐fluoro­phenyl)­methyl­enebis(3‐hydroxy‐5,5‐di­methyl‐2‐cyclo­hexen‐1‐one), C₂₃H₂₇FO₄, (I), 2,2′‐(4‐chloro­phenyl)­methyl­enebis(3‐hy­droxy‐5,5‐dimethyl‐2‐cyclo­hexen‐1‐one), C₂₃H₂₇ClO₄, (II), 2,2′‐(4‐hydroxy­phenyl)­methyl­enebis(3‐hydroxy‐5,5‐di­methyl‐2‐cyclo­hexen‐1‐one), C₂₃H₂₈O₅, (III), 2,2′‐(4‐methyl­phenyl)­methyl­enebis(3‐hydroxy‐5,5‐di­methyl‐2‐cyclo­hexen‐1‐one), C₂₄H₃₀O₄, (IV), 2,2′‐(4‐methoxy­phenyl)­methyl­enebis(3‐hy­droxy‐5,5‐di­methyl‐2‐cyclo­hexen‐1‐one), C₂₄H₃₀O₅, (V), and 2,2′‐(4‐N,N′‐di­methyl­amino­phenyl)­methyl­enebis(3‐hydroxy‐5,5‐di­methyl‐2‐cyclo­hexen‐1‐one), C₂₅H₃₃NO₄, (VI). Structures (III) to (VI) of these bis‐dimedone derivatives show nearly the same packing pattern irrespective of the different substituent in the para position of the aromatic ring. However, (II) does not fit into this scheme, although the Cl atom is a substituent not too different from the others. The different packing of the fluoro compound, (I), can be explained by the fact that it crystallizes with two mol­ecules in the asymmetric unit, which show a different conformation of the dimedone ring. On the other hand, (I) shows a similar packing pattern to bis(2‐hydroxy‐4,4‐di­methyl‐6‐oxo‐1‐cyclo­hexenyl)­phenyl­methane, a compound containing an aromatic ring without any substituent and with Z′ = 2.