The NiII,HgII and CuII complexes of 12‐membered‐ring mixed‐donor macrocycles

The structures of di­aqua(1,7‐dioxa‐4‐thia‐10‐aza­cyclo­do­decane)­nickel dinitrate, [Ni(C₈H₁₇NO₂S)(H₂O)₂](NO₃)₂, (I), bis­(nitrato‐O,O′)(1,4,7‐trioxa‐10‐aza­cyclo­do­decane)­mercury, [Hg(NO₃)₂(C₈H₁₇NO₃)], (II), and aqua­(nitrato‐O)(1‐oxa‐4,7,10‐tri­aza­cyclo­do­decane)copper nitrate, [Cu(NO₃)(C₈H₁₉N₃O)(H₂O)]NO₃, (III), reveal each macrocycle binding in a tetradentate manner. The conformations of the ligands in (I) and (III) are the same and distinct from that identified for (II). These differences are in agreement with molecular‐mechanics predictions of ligand conformation as a function of metal‐ion size.     

A highly functionalized ferrocenyl­pyrazolo­[2,3‐a]­pyridine

The crystal structure of [2‐(4‐bromo­phenyl)‐4‐cyano‐5‐ferrocenyl­pyrazolo­[2,3‐a]­pyridin‐7‐yl]­aceto­nitrile, C₂₆H₁₇N₄FeBr or [Fe(C₅H₅)(C₂₁H₁₂BrN₄)], shows that the pyrazolo­pyridine ring system (PP), the bromo­phenyl ring (BP) and the cyclo­penta­diene ring (Cp) are nearly planar. The PP ring system is twisted out of the plane of the BP and Cp rings by about 20°.     

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.     

(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).     

2‐{[Tris(hydroxymethyl)methyl]aminomethylene}cyclohexa‐3,5‐dien‐1(2H)‐one and its 6‐hydroxy and 6‐methoxy derivatives

The title compounds, 2‐{[tris­(hydroxy­methyl)­methyl]­amino­methyl­ene}cyclo­hexa‐3,5‐dien‐1(2H)‐one, C₁₁H₁₅NO₄, (I), 6‐hydroxy‐2‐{[tris­(hydroxy­methyl)­methyl]­amino­methyl­ene}­cyclo­hexa‐3,5‐dien‐1(2H)‐one, C₁₁H₁₅NO₅, (II), and 6‐methoxy‐2‐{[tris­(hydroxy­methyl)­methyl]­amino­methyl­ene}­cyclo­hexa‐3,5‐dien‐1(2H)‐one, C₁₂H₁₇NO₅, (III), adopt the keto–amine tautomeric form, with the formal hydroxy H atom located on the N atom, and the NH group and oxo O atom display a strong intramolecular N—H⋯O hydrogen bond. The N—H⋯O hydrogen‐bonded rings are almost planar and coupled with the cyclo­hexa­diene rings. The carbonyl O atoms accept two other H atoms from the alcohol groups of adjacent mol­ecules in (I), and one from the alcohol and one from the phenol group in (II), but from only one alcohol H atom in (III).     

Propynylferrocene and (phenyl­ethyn­yl)­ferrocene

The title compounds, propynylferrocene, [Fe(C₅H₅)(C₈H₇)], (I), and (phenyl­ethyn­yl)ferrocene, [Fe(C₅H₅)(C₁₃H₉)], (II), are stabilized by weak C—H⋯π inter­actions. The C[triple‐bond]C bond distances in these mol­ecules are in the range 1.182 (3)–1.192 (3) Å. In (II), the ferrocenyl and phenyl groups are perpendicular, making an angle of 89.06 (13)°, which is a rare occurrence.     

Structural properties of a series of photochromic fluorinated indolylfulgides

Fluorinated indolyl­fulgides are a class of photochromic organic compounds that meet many of the requirements for use as optical memory media and optical switches. The X‐ray crystal structures of a series of five photochromic fluorinated indolyl­fulgides have been determined, namely (3Z)‐3‐[1‐(1,2‐di­methyl‐1H‐indol‐3‐yl)‐2,2,2‐tri­fluoro­ethyl­idene]‐4‐(1‐methyl­ethyl­idene)­dihydrofuran‐2,5‐dione (tri­fluoro­methyl­iso­propyl­idene­indolyl­fulgide), C₁₉H₁₆F₃NO₃, (I), (3Z)‐3‐[1‐(1,2‐dimethyl‐1H‐indol‐3‐yl)‐2,2,3,3,3‐penta­fluoro­propyl­idene]‐4‐(1‐methyl­ethyl­idene)­dihydrofuran‐2,5‐dione (penta­fluoro­ethyl­iso­propyl­idene­indolyl­fulgide), C₂₀H₁₆F₅NO₃, (II), (3Z)‐3‐[1‐(1,2‐di­methyl‐1H‐indol‐3‐yl)‐2,2,3,3,4,4,4‐hepta­fluoro­butyl­idene]‐4‐(1‐methyl­ethyl­idene)­dihydrofuran‐2,5‐dione (hepta­fluoro­propyl­iso­propyl­idene­indolyl­fulgide), C₂₁H₁₆F₇NO₃, (III), (3Z)‐3‐[1‐(1,2‐di­methyl‐1H‐indol‐3‐yl)‐2,2,2‐tri­fluoro­ethyl­idene]‐4‐(tri­cyclo­[3.3.1.1^3,7]­decyl­idene­)dihydrofuran‐2,5‐dione (tri­fluoro­methyl­adamantyl­idene­indolyl­fulgide), C₂₆H₂₄F₃NO₃, (IV), and (3Z)‐3‐[1‐(1,2‐di­methyl‐1H‐indol‐3‐yl)‐2,2,3,3,4,4,4‐hepta­fluoro­butyl­idene]‐4‐(tri­cyclo­[3.3.1.1^3,7]­decyl­idene­)dihydrofuran‐2,5‐dione (hepta­fluoro­propyl­adamantylidenein­dolyl­fulgide), C₂₈H₂₄F₇NO₃, (V). The photochromic property of fulgides is based on the photochemically allowed electrocyclic ring closure of a hexatriene system to form a cyclo­hexa­diene. For each fulgide examined, the bond lengths within the hexatriene system alternate between short and long, as expected. Comparing the structures of the five fulgides with each other demonstrates no significant difference in bond lengths, bond angles or dihedral angles within the hexatriene systems. The distance between the bond‐forming C atoms at each end of the hexatriene system does vary. Correlations of structural properties with optical properties are addressed.     

Hydrido‐sulfido‐bridged triangular Os3 cluster compounds with different phosphine ligand substitution patterns

In the course of our studies of trinuclear osmium cluster complexes with bridging sulfido and hydrido ligands, the new compounds Os₃(μ‐H)(μ‐SR)(CO)₉(PHCy₂) (Cy = cyclo­hexyl) with R = phenyl, (I) (nona­carbonyl‐1κ³C,2κ³C,3κ³C‐di­cyclo­hexyl­phosphine‐3κP‐μ‐hydrido‐1:2κ²H‐μ‐phenyl­thio‐1:2κ²S‐triangulo‐triosmium), [Os₃H(C₆H₅S)(C₁₂H₂₃P)(CO)₉], and R = naphthyl, (II) [nona­carbonyl‐1κ³C,2κ²C,3κ⁴C‐di­cyclo­hexyl­phosphine‐2κP‐μ‐hydrido‐1:2κ²H‐μ‐(2‐naphthyl­thio)‐1:2κ²S‐triangulo‐triosmium], [Os₃H(C₁₀H₇S)(C₁₂H₂₃P)(CO)₉], were prepared. We report on these two phosphine‐substituted complexes, which exhibit perceptible changes of the Os—Os bond parameters due to the ligand‐substitution pattern.     

Chiral and meso‐bis([2.2]­para­cyclo­phan‐4‐yl)­methane and meso‐bis­([2.2]­para­cyclo­phan‐4‐yl) sulfide

The [2.2]­para­cyclo­phane groups of the title compounds, chiral and meso‐bis­(tri­cyclo­[8.2.2.2^4,7]­hexa­deca‐4,6,10,12,13,15‐hexa­en‐5‐yl)­methane (the former as a racemate), C₃₃H₃₂, and meso‐bis­(tri­cyclo­[8.2.2.2^4,7]­hexa­deca‐4,6,10,12,13,15‐hexa­en‐5‐yl) sulfide, C₃₂H₃₀S, show the characteristic structural features of the parent compound [2.2]­para­cyclo­phane and the related compound di­methylbis([2.2]­para­cyclo­phan‐4‐yl)­silane, C₃₄­H₃₆­Si: the aromatic rings are puckered, resulting in a boat conformation. The planes of the four coplanar C atoms are slightly twisted with respect to each other. The Csp³—Csp³ bond lengths of the ethyl­ene bridges are elongated by the electronic and steric effects of the skeleton.     

Supramolecular aggregation of two hydroxy­carboxylic acid derivatives

The crystal structures of 7,7‐dicyclo­but­yl‐5‐hydroxy­meth­yl‐6‐oxabicyclo­[3.2.1]octa­ne‐1‐carboxylic acid, C₁₇H₂₆O₄, (I), and 1‐(hydroxy­meth­yl)‐7‐oxaspiro­[bicyclo­[3.2.1]octa­ne‐6,1′‐cyclo­penta­ne]‐5‐carboxylic acid, C₁₃H₂₀O₄, (II), determined at 170 K, show that the conformation of the hydroxy­meth­yl group (anti or gauche) affects the dimensionality (one‐ or two‐dimensional) of the supramolecular structures via O—H⋯O hydrogen bonds. In (I), the carbox­yl and hydroxy­meth­yl groups inter­act with themselves, forming a one‐dimensional step‐ladder, while in (II), a two‐dimensional structure is made up of carboxylic acid centrosymmetric R₂²(8) dimers connected by hydrox­yl‐to‐ether contacts.     

1‐Acetyl‐3‐ferrocenyl‐5‐methyl‐1H‐pyrazole and 1‐acetyl‐5‐ferrocenyl‐3‐(2‐pyrid­yl)‐1H‐pyrazole

Mol­ecules of 1‐acetyl‐3‐ferrocenyl‐5‐methyl‐1H‐pyrazole, [Fe(C₅H₅)(C₁₁H₁₁N₂O)], form a centrosymmetric dimer generated by a combination of one C—H⋯π(pyrazole) and one C—H⋯π(cyclo­penta­dienyl) inter­action. The dimers are linked by C—H⋯π inter­actions, involving the pyrazole rings as acceptors, into layers parallel to (10). Mol­ecules of 1‐acetyl‐5‐ferrocenyl‐3‐(2‐pyrid­yl)‐1H‐pyrazole, [Fe(C₅H₅)(C₁₅H₁₂N₃O)], are linked by C—H⋯O inter­actions into a chain running in the [010] direction. Two chains of this type passing through each unit cell are connected by O⋯π(pyridyl) inter­actions into an [010] double chain.     

cyclo(‐Cha–Oxz–d‐Val–Thz–Ile–Oxz–d‐Val–Thz‐) N,N‐di­methyl­acetamide dihydrate: a square form of cyclo­hexyl­alanine‐incorporated ascidiacycl­amide having the strongest cytotoxicity

The title compound, 1‐cyclo­hexyl­methyl‐1‐de(1‐methyl­propyl)­asci­dia­cycl­amide N,N‐di­methyl­acet­amide di­hy­drate, C₃₉H₅₆N₈O₆S₂·C₄H₉NO·2H₂O, a cyclo­hexyl­alanine‐incorporated ascidiacycl­amide analogue ([Cha]ASC), shows a square form similar to natural ASC. On the other hand, CD (circular dichroism) spectra showed [Cha]ASC to have a folded structure in solution, making it the second known analogue to show a discrepancy between its crystal and solution structures. Moreover, the cytotoxicity of [Cha]ASC (ED₅₀ = 5.6 µg ml⁻¹) was approximately two times stronger than that of natural ASC or a related phenyl­alanine‐incorporated analogue, viz. cyclo(‐Phe–Oxz–d ‐Val–Thz–Ile–Oxz–d ‐Val–Thz‐) ([Phe]ASC), and was confirmed to be associated with the square form. However, [Phe]ASC was previously shown to be folded in the crystal structure, which suggests that the difference between the aromatic and aliphatic rings affects the molecular folding of the ASC mol­ecule.     

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.     

Two hydro­chlorides of 7‐methyl‐3,7,11,17‐tetra­aza­bi­cyclo­[11.3.1]­heptadeca‐1(17),13,15‐triene

The X‐ray structure determinations of the two title com­pounds, namely 7‐methyl‐7,17‐di­aza‐3,11‐diazo­niabi­cyclo[11.3.1]­hep­ta­deca‐1(17),13,15‐triene dichloride monohydrate, C₁₄H₂₆N₄²⁺·2Cl^?·H₂O, (I), and 7‐methyl‐17‐aza‐3,7,11‐triazo­niabi­cyclo­[11.3.1]­heptadeca‐1(17),13,15‐triene 2.826‐chloride 0.174‐nitrate, C₁₄H₂₇N₄³⁺·2.826Cl^?·0.174NO₃^?, (II), are re­ported. Protonation occurs at the secondary amine N atoms in (I) and at all three amine N atoms in (II) to which the Cl^? ions are linked via N—H?Cl hydrogen bonds. The macrocyclic hole is quite different in both structures, as is observed by comparing particularly the N3?N4 distances [2.976 (4) and 4.175 (4) Å for (I) and (II), respectively]. In (II), a Cl^? ion alternates with an NO₃^? ion in a disordered structure.     

cis‐ and trans‐2‐(4‐tert‐Butylcyclohexyloxy)‐1,3,5‐trinitrobenzene

The structures of cis‐ and trans‐2‐(4‐tert‐butyl­cyclo­hexyl­oxy)‐1,3,5‐tri­nitro­benzene, C₁₆H₂₁N₃O₇, (I) and (II), respectively, were determined at low temperature in order to obtain accurate structural parameters for comparison purposes. The C_alkyl—O_ether bond distances are 1.497 (2) and 1.491 (2) Å for (I) and (II), respectively.     

The one‐electron oxidation product of a metallocenyl‐terminated cyanine

The 1‐(2,3,4,5,1′,2′,3′,4′‐octa­methyl­ferrocen‐1‐yl)‐3‐(ruth­eno­cen­yl)­allylium cation readily undergoes one‐electron oxidation to a dication in which an octa­methyl­ferrocenium moiety is bridged by a vinyl­ene group to a [(η⁶‐fulvene)(η⁵‐cyclo­penta­dienyl)­ruthenium]⁺ moiety. In the title compound, 1‐(2,3,4,5,1′,2′,3′,4′‐octa­methyl­ferrocen‐1‐yl)‐3‐(ruth­eno­cen­ylidene)prop‐1‐enium(2+) bis­(tetra­fluoro­borate), [Fe­Ru­(C₅H₅)(C₉H₁₃)(C₁₇H₁₉)]­(BF₄)₂, the C—C bond lengths in the bridge (average for two independent mol­ecules) are, starting from the ipso octa­methyl­ferrocenium carbon and ending at the exo carbon of the coordinated fulvene, 1.455 (6), 1.344 (3) and 1.449 (8) Å, indicating a localized electronic structure.     

Exo Diels–Alder adducts between ortho‐ and para‐N‐acetoxy­phenyl­male­imides and furan

In exo‐2‐(3,5‐dioxo‐10‐oxa‐4‐aza­tri­cyclo­[5.2.1.0^2,6]­dec‐8‐en‐4‐yl)­phenyl acetate, C₁₆H₁₃NO₅, the plane of the acetoxy group lies almost perpendicular to that of the phenyl ring [dihedral angle = 89.8 (1)°], in contrast with the smaller deviations found in the para isomer exo‐4‐(3,5‐dioxo‐10‐oxa‐4‐aza­tri­cyclo­[5.2.1.0^2,6]­dec‐8‐en‐4‐yl)­phenyl acetate, C₁₆H₁₃NO₅, these being 63.6 (1) and 37.0 (1)° for the two crystallographically independent mol­ecules. Irrespective of the position of the acetoxy group, both compounds pack through soft C—H⋯X (X is O or phenyl) interactions, forming interlinked centrosymmetric tetramers in the bc plane.     

cis‐Tetracarbonylbis(tricyclohexyl­phosphine)molybdenum(0) and pentacarbonyl(tricyclohexylphos­phine)molybdenum(0)

In the present redetermination of the complex cis‐tetra­carbonyl­bis­(tri­cyclo­hexyl­phosphine)molybdenum(0), (I), [Mo(C₁₈H₃₃P)₂(CO)₄] or cis‐{η¹‐[P(C₆H₁₁)₃]₂}Mo(CO)₄, the Mo atom has a distorted octahedral geometry with a large P—Mo—P angle of 104.8 (1)°. A strong trans influence on the carbonyls in (I) is seen in a shortening of the Mo—C and a lengthening of the C—O distances opposite the phosphines compared with those that are cis. This influence is greatly diminished in the complex penta­carbonyl­(tri­cyclo­hexyl­phosphine)­molyb­denum(0), (II), [Mo(C₁₈H₃₃P)(CO)₅] or {η¹‐[P(C₆H₁₁)₃]}­Mo(CO)₅, the core of which has a slightly distorted C_4v geometry.     

Di­chloro­(norborna­diene)­platinum(II): a comparison with di­chloro­(cyclo­octa­diene)­platinum(II)

The crystal structure of the title compound, (bi­cyclo­[2.2.1]­hepta‐2,5‐diene)­di­chloro­platinum(II), [PtCl₂(C₇H₈)], has been determined from single‐crystal X‐ray analysis. The coordination sphere about the Pt atom is pseudo‐square planar, with shorter Pt—C distances than in the corresponding di­chloro­(cyclo­octa­diene)­platinum(II) complex.     

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.