4,7‐Bis(4‐pyridyl­ethynyl)‐2,1,3‐benzo­thia­diazo­le and its dipyridinium diperchlorate

The title compound, C₂₀H₁₀N₄S, and its dipyridinium salt, 4,4′‐(2,1,3‐benzo­diazol‐4,7‐diyl­diethynyl)­dipyridinium diperchlorate, C₂₀H₁₂N₄S²⁺·2ClO₄^?, display bond alternation in the 2,1,3‐benzo­thia­diazo­le rings, which suggests their quinonoid character. The dipyridinium dication mol­ecules stack along the a axis and form a dimer with short S?N interheteroatom contacts [3.146 (4) Å] between the two 1,2,5‐thia­diazo­le rings. The dimer is surrounded by the perchlorate anions with which it forms a large number of intermolecular N—H?O and C—H?O hydrogen bonds.     

Hydro­gen‐bonded dimers in N‐(2‐nitro­phenyl­thio)­saccharin

In the title compound, 2‐(2‐nitro­phenyl­thio)‐1,2‐benzo­thia­zol‐3(2H)‐one 1,1‐dioxide, 2‐O₂NC₆H₄S(C₇H₄NO₃S) or C₁₃H₈N₂­O₅S₂, the planes of the saccharin and nitro­phenyl­thiol­ate portions are almost orthogonal. The mol­ecules are linked by C—H?O=S hydrogen bonds [C?O 3.308 (3) Å, H?O 2.44 Å and C—H?O 155°] into cyclic centrosymmetric R²₂(16) dimers, reinforced by aromatic π?π stacking interactions between the nitrated aryl rings.     

2,5‐Bis(methylthio)‐1,4‐benzo­quinone and 2‐methyl‐3‐(methylsulfonyl)benzo[b]thiophene

The structure of 2,5‐bis­(methyl­thio)‐1,4‐benzo­quinone, C₈H₈O₂S₂, is composed of an essentially planar centrosymmetric benzo­quinone substituted with two methyl­thio groups. The important bond distances are S—Csp³ 1.788 (2) and S—Csp² 1.724 (2) Å, and the two Csp²—Csp² distances are 1.447 (3) and 1.504 (3) Å, which differ significantly. There are short S?S interactions of 3.430 (1) Å and Csp²—H?O‐type contacts forming a dimeric motif with graph set R₂²(8). The structure of 2‐methyl‐3‐(methyl­sulfonyl)­benzo­[b]­thio­phene, C₁₀H₁₀O₂S₂, is composed of an essentially planar benzo­thio­phene moiety substituted with methyl and methyl­sulfonyl groups. The mean values of the important bond distances are endocyclic S—Csp² 1.734 (3), S=O 1.434 (4) and C—C_aromatic 1.389 (10) Å. The exocyclic S—Csp² and S—Csp³ distances are 1.759 (4) and 1.763 (5) Å, respectively.     

3,9‐Bis(dicyanomethylene)‐2,4,8,10‐tetrathiaspiro[5.5]undecane

The title compound, 2,2′‐(2,4,8,10‐tetra­thia­spiro­[5.5]­undec­ane‐3,9‐diyl­idene)­bis­(propane­di­nitrile), C₁₃H₈N₄S₄, has been designed and synthesized for use as a potential new organic molecular electronic material. The spiro‐annulated structure has twofold symmetry and is formed by two equal push–pull ethyl­ene units, with the cyclo­alkyl­thio groups as electron donors and the cyano groups as electron acceptors. The intermolecular S?N non‐bonded separation within a layer in the lattice is 3.296 (6) Å, indicating a strong intermolecular interaction between the cyano groups and the S atoms, while the S atoms in two neighbouring mol­ecules have a shortest S?S contact of 3.449 (3) Å. In addition, attractive C—H?N and C—H?S interactions bridge adjacent mol­ecules either within a layer or between layers. In short, these four types of intermolecular interactions combine to form an extended three‐dimensional network in the lattice, resulting in a highly ordered array of molecular packing.     

Tris(2,2′‐bipyridyl‐N,N′)­nickel(II) thio­sulfate heptahydrate

The structure of the title compound, [Ni(C₁₀H₈­N₂)₃](S₂O₃)·7H₂O, consists of monomeric Ni(bipy)₃²⁺ cations embedded in an anionic network made up of S₂O₃^2? ions and hydration water mol­ecules. The structure presents the unusual feature of two neighbouring thio­sulfates approaching linearly head‐to‐head with an unusually short S?S contact distance of 3.25 Å.     

3‐[(2‐Oxo‐1‐naphthylidene)methyl­amino]­benzoic acid

The title compound, C₁₈H₁₃NO₃, exists as a keto­amino tautomer implying a fairly short N—H?O intramolecular hydrogen bond between the 2‐naphthalenone and amino moieties [N?O 2.531 (3) Å] which is enhanced by the π‐electron delocalization effect. The naphthald­imine and 3‐carboxy­phenyl fragments are inclined at an angle of 4.41 (7)°, so the mol­ecule is almost planar. The mol­ecules are connected by intermolecular O—H?O hydrogen bonds between the carboxy and keto O atoms, forming infinite chains around the twofold screw axes parallel to b .     

Novel heterocyclic inhibitors of matrix metalloproteinases: three 6H‐1,3,4‐thiadiazines

The title compounds, (2S)‐N‐[5‐(4‐chloro­phenyl)‐2,3‐di­hydro‐6H‐1,3,4‐thia­diazin‐2‐yl­idene]‐2‐[(phenyl­sulfonyl)­amino]­pro­pan­amide, C₁₈H₁₇ClN₄O₃S₂, (I), (2R)‐N‐[5‐(4‐fluoro­phenyl)‐6H‐1,3,4‐thia­diazin‐2‐yl]‐2‐[(phenyl­sulfonyl)amino]­propan­amide, C₁₈H₁₇FN₄O₃S₂, (II), and (2S)‐N‐[5‐(5‐chloro‐2‐thienyl)‐6H‐1,3,4‐thia­diazin‐2‐yl]‐2‐[(phenyl­sulfonyl)­amino]­propan­amide, C₁₆H₁₅ClN₄O₃S₃, (III), are potent inhibitors of matrix metalloproteinases. In all three compounds, the thia­diazine ring adopts a screw‐boat conformation. The mol­ecules of compound (I) show a short intramolecular N_Ala—H?N_exo hydrogen bond [N?N 2.661 (3) Å] and are linked into a chain along the c axis by N_endo—H?S_endo and N_endo—H?O_Ala hydrogen bonds [N?S 3.236 (3) and N?O 3.375 (3) Å] between neighbouring mol­ecules. In compound (II), the mol­ecules are connected antiparallel into a chain along the a axis by N_exo—H?O_Ala and N_Ala—H?N_endo hydrogen bonds [N?O 2.907 (6) and N?N 2.911 (6) Å]. The mol­ecules of compound (III) are dimerized antiparallel through N_exo—H?N_endo hydrogen bonds [N?N 2.956 (7) and 2.983 (7) Å]. The different hydrogen‐bonding patterns can be explained by an amido–imino tautomerism (prototropic shift) shown by different bond lengths within the 6H‐1,3,4‐thia­diazine moiety.     

7‐Phenyl‐1‐oxa‐4‐thiaspiro[4.5]decan‐7‐ol stereoisomers

The stereoisomers of 7‐phenyl‐1‐oxa‐4‐thia­spiro­[4.5]­decan‐7‐ol, C₁₄H₁₈O₂S, have the same stereochemistry at the C atom bearing an OH group, i.e. axial OH and equatorial phenyl groups. However, the acetal S and O atoms are axial and equatorial, respectively, in one isomer and reversed in the second. Furthermore, the crystals of one isomer are composed of hydrogen‐bonded mol­ecules involving the hydroxyl H atom and the O atom of the five‐membered heterocyclic ring, with an O?O distance of 2.962 (3) Å, forming a polymeric chain along the b axis. The asymmetric unit of the other isomer is composed of two mol­ecules, wherein hydroxyl H atoms and the O atoms of the five‐membered heterocyclic rings display intramolecular O—H?O hydrogen bonds with O?O separations of 2.820 (2) and 2.834 (2) Å.     

Precursor of a β‐lactamase inhibitor: allyl (4S,8S,9R)‐10‐[(E)‐ethyl­idene]‐4‐methoxy‐11‐oxo‐1‐aza­tri­cyclo­[7.2.0.03,8]­undec‐2‐ene‐2‐carboxyl­ate

The molecular structure of the title tricyclic compound, C₁₇H₂₁NO₄, which is the immediate precursor of a potent synthetic inhibitor {Lek157: sodium (8S,9R)‐10‐[(E)‐ethyl­idene]‐4‐methoxy‐11‐oxo‐1‐aza­tri­cyclo­[7.2.0.0^3,8]­undec‐2‐ene‐2‐carboxyl­ate} with remarkable potency, provides experimental evidence for the previously modelled relative position of the fused cyclo­hexyl ring and the carbonyl group of the β‐lactam ring, which takes part in the formation of the initial tetrahedral acyl–enzyme complex. In this hydro­phobic mol­ecule, the overall geometry is influenced by C—H?O intramolecular hydrogen bonds [3.046 (4) and 3.538 (6) Å, with corresponding normalized H?O distances of 2.30 and 2.46 Å], whereas the mol­ecules are interconnected through intermolecular C—H?O hydrogen bonds [3.335 (4)–3.575 (5) Å].     

4‐Fluoro‐2‐(phospho­no­methyl)­benzene­sulfonic acid monohydrate

The title compound, C₇H₈FO₆PS·H₂O, contains both phospho­nic and sulfonic acid functionalities. An extensive network of O—H?O hydrogen bonds is present in the crystal structure. The three acidic protons are associated with the phospho­nate group. Two protons experience typical hydrogen‐bond contacts with the sulfonate‐O atoms, while the third has a longer covalent bond of 1.05 (3) Å to the phospho­nate‐O atom and a short hydrogen‐bond contact of 1.38 (3) Å to the water O atom (all O—H?O angles are in the range 162–175°). The sulfonate group is positioned so that one S—O bond is nearly coplanar with the phenyl ring [torsion angle O—S—C—C ?8.6 (2)°]. The phospho­nate group is oriented approximately perpendicular to the ring [torsion angle P—C—C—C 99.2 (2)°] with one P—O bond anti to the benzyl C—C bond. The mol­ecules pack in layers in the b–c plane with the water mol­ecules in between adjacent pairs of inverted layers.     

5‐Nitro‐N‐phenyl‐2‐thio­fur­amide

The title compound, C₁₁H₈N₂O₃S, crystallizes with two crystallographically independent mol­ecules, which are conformationally almost identical, per asymmetric unit. The dihedral angles between the phenyl and 2‐thio­fur­amide planes are 46.3 (1) and 47.0 (1)° for the first and second mol­ecule, respectively. Strong intramolecular N—H?O hydrogen bonds [N?O 2.664 (2) and 2.661 (2) Å] dictate an anti conformation of the C=S groups in relation to the furan‐O atoms.     

2,6‐Di­phenylthiapyran‐4‐one

In the title compound, 2,6‐di­phenyl­thia­cyclo­hexan‐4‐one, C₁₇H₁₆OS, mirror site symmetry is retained by the mol­ecule in the solid state in the absence of C—H?X hydrogen bonds. The crystal structure is stabilized by van der Waals interactions, the shortest S?O and C?O contacts being 3.567 (2) and 3.512 (3) Å, respectively.     

The new chiral ligand 3‐ethoxy‐4‐[(1R,2S)‐(2‐hydroxy‐1,2‐di­phenyl­ethyl)­amino]‐3‐cyclo­butene‐1,2‐dione

The asymmetric unit of C₂₀H₁₉NO₄ contains two mol­ecules with slightly different conformations. In the crystal, the mol­ecules are linked by O—H?O and N—H?O hydrogen bonds [O?O 2.764 (3) and 2.811 (3) Å; N?O 2.907 (3) and 2.968 (3) Å] to form a two‐dimensional network.     

5‐Chloro‐N‐(2‐hydroxy‐5‐methyl­phenyl)­salicyl­ald­imine

The title compound, N‐(5‐chloro‐2‐oxido­benzyl­idene)‐2‐hydroxy‐5‐methyl­anilinium, C₁₄H₁₂ClNO₂, is a tridentate Schiff base with almost planar molecules. Each mol­ecule contains a strong intramolecular N—H?O hydrogen bond [2.576 (2) Å]. There is also an intermolecular O—H?O hydrogen bond [2.695 (2) Å] linking neighbouring mol­ecules into infinite chains along the [101] direction.     

Diphenyl(2‐thioxo‐1,3‐dithiole‐4,5‐di­thiolato‐S,S′)plumbane at 295 K and diphenyl(2‐thioxo‐1,3‐dithiole‐4,5‐di­thiolato‐S,S′)stannane at 150 K

Molecules of di­phenyl(2‐thio­xo‐1,3‐di­thiole‐4,5‐di­thiol­ato‐S,S′)­plumbane, [Pb(C₃S₅)(C₆H₅)₂], are linked into sheets via two intermolecular Pb?S_thione interactions of 3.322 (4) and 3.827 (4) Å; the Pb centre has a distorted octahedral geometry. In contrast, mol­ecules of ­di­phenyl(2‐thio­xo‐1,3‐di­thiole‐4,5‐di­thiol­ato‐S,S′)­stannane, [Sn(C₃S₅)(C₆H₅)₂], are linked into chains via a single intermolecular Sn—S_thione interaction of 2.8174 (9) Å; the Sn centre has a distorted trigonal‐bipy­ramidal geometry.     

5‐Methyl‐2‐thiouracil

The molecular structure of the title compound, also known as 2‐thio­thymine [systematic name: 2,3‐di­hydro‐5‐methyl‐2‐thioxopyrimidin‐4(1H)‐one], C₅H₆N₂OS, is similar to that of thymine, with only small changes in the ring structure, apart from a significant difference at the substitution site [S=C = 1.674 (1) Å]. The mol­ecules are connected by hydrogen bonds, with N—H?O = 2.755 (2) Å and N—H?S = 3.352 (1) Å. The hydrogen‐bond network is different from that in thymine, since it involves all the donor and acceptor atoms.     

Model porphyrin precursors: 1,2,4,5‐tetrakis(cyanomethyl)­benzene,methyl 3,4,5‐triacetoxy­benzoate and 2‐(N‐phthalimidomethyl)benzoic acid

In the crystalline state, the centrosymmetric mol­ecule 1,2,4,5‐tetrakis­(cyano­methyl)­benzene, C₁₄H₁₀N₄, has one cyano­methyl group in the benzene plane and one cyano­methyl group rotated 67.2 (2)° out of the benzene plane. Molecules of methyl 3,4,5‐tri­acetoxy­benzoate, C₁₄H₁₄O₈, form chains with each mol­ecule twisted 89.6 (1)° from the preceding mol­ecule. In this orientation, a close C—H?O contact is formed, with an H?O distance of 2.34 Å. The structure of 2‐(N‐phthalimido­methyl)­benzoic acid, C₁₆H₁₁NO₄, reveals hydrogen‐bonded dimers linked by the carboxyl groups of adjacent mol­ecules. The O4?O3 distance is 2.636 (2) Å and the O4—H?O3 angle is 171 (2)°.     

(1S,2R,2′S)‐ and (1S,2S,2′S)‐1‐phenyl‐2‐phenyl­thio‐2‐(tetra­hydro­pyran‐2′‐yl­thio)­ethanol diastereoisomers at 193 K

In the synthesis of 1‐phenyl‐2‐phenyl­thio‐2‐(tetra­hydro­pyran‐2‐yl­thio)­ethanol, C₁₉H₂₂O₂S₂, four diastereoisomers are formed. Two non‐centrosymmetric enantiomeric forms which crystallize in space groups P2₁2₁2₁ and Pna2₁ are presented. The former has an intramolecular hydrogen bond between the hydroxyl group and the O atom of the tetra­hydro­pyran ring. In the latter isomer, the hydroxyl group forms an intermolecular hydrogen bond to the O atom of the tetra­hydro­pyran­yl group of a neighbouring mol­ecule, joining the mol­ecules into chains in the c‐axis direction; the O?O distances are 2.962 (4) and 2.764 (3) Å, respectively. The tetra­hydro­pyran rings are in chair conformations in both isomers and the S side chain has an equatorial orientation in the former, but an axial orientation in the latter mol­ecule.     

Tetrameric triphenylsilanol, (Ph3SiOH)4, and the adduct (Ph3SiOH)2–di­methyl sulfoxide,both at 120 K,and the adduct (Ph3SiOH)4–1,4‐dioxan at 150 K: interplay of O—H⋯O and C—H⋯π(arene) interactions

The structure of tetrameric tri­phenyl­silanol, C₁₈H₁₆OSi, (I), has been re‐investigated at 120 (2) K. The hydroxyl H atoms were readily located and one of the arene rings is disordered over two closely positioned sets of sites. The mol­ecules are linked into cyclic tetramers, having approximate (S₄) symmetry, via O—H?O hydrogen bonds [H?O 1.81–1.85 Å, O?O 2.634 (3)–2.693 (3) Å and O—H?O 156–166°]. At ambient temperature, there are indications of multiple disorder of the phenyl‐ring sites. In bis­(tri­phenyl­silanol) di­methyl sulfoxide solvate, 2C₁₈H₁₆OSi·C₂H₆OS, (II), the di­methyl sulfoxide component is disordered across a twofold rotation axis in C2/c, and the molecular components are linked by a single O—H?O hydrogen bond [H?O 1.85 Å, O?O 2.732 (2) Å and O—H?O 172°] into three‐mol­ecule aggregates, which are themselves linked into a single three‐dimensional framework by two C—H?π(arene) interactions. In tetrakis­(tri­phenyl­silanol) 1,4‐dioxan solvate, 4C₁₈H₁₆OSi·C₄H₈O₂, (III), the 1,4‐dioxan component lies across an inversion centre in space group P and centrosymmetric five‐mol­ecule aggregates are linked by paired C—H?π(arene) interactions to form molecular ladders.     

2,3‐Dihydro‐3‐methyl‐2‐nitrimino‐1,3‐thiazole

The title compound {alternatively, 3‐methyl‐2‐[oxido(oxo)hydrazono]‐2,3‐dihydro‐1,3‐thiazole}, C₄H₅N₃O₂S, was obtained by methyl­ation of N‐(2‐thia­zolyl)­nitr­amine. The molecule lies on a mirror plane and the thia­zole ring is planar, regular in shape and aromatic. The S atom participates in the aromatic sextet via an electron pair on the 3p_z orbital. In the crystal, the mol­ecules are arranged in parallel layers, bound to each other by weak C—H?O and C—H?N hydrogen bonds and by S?O dipolar interactions, with an interlayer separation of 3.23 Å.