Ethyl 5-hy­droxy-6-oxo-4-phenyl-5,6-dihydro-4H-cyclo­penta­[b]thio­phene-5-carboxyl­ate

In the title mol­ecule, C16H14O4S, the dihydro­cyclo­penta­thio­phenone ring system is almost planar, with an r.m.s. deviation of 0.060 Å from the best fit plane through all nine non-H atoms. The cyclo­penta­none ring adopts a severely flattened envelope conformation with the C atom carrying the OH and ethylcarboxylate substituents at the flap. This atom lies only 0.185 (3) Å from the plane through the other four C atoms. The phenyl substituent is inclined at 43.37 (5)° to the dihydro­cyclo­penta­thio­phenone mean plane. In the crystal, mol­ecules are linked by pairs of O—H⋯O hydrogen bonds, forming inversion dimers with R 2 2(10) ring motifs. Weak C—H⋯O hydrogen bonds also link mol­ecules into chains along c, while an approximately orthogonal set of C—H⋯O contacts form chains along b, resulting in layers lying parallel to (100). Inversion dimers also form through weaker R 2 2(12) C—H⋯S contacts, which combine with C—H⋯O contacts to form stacks along b

1,4-Bis(iodo­meth­yl)benzene

The centrosymmetric title compound, C8H8I2, was prepared by metathesis from the dibromo analogue. In the crystal structure, weak C—H⋯I inter­actions link the mol­ecules into stacks down the b axis. The structure is further stabilized by short I⋯I contacts [3.8433 (2) Å], forming undulating sheets in the (101) plane

6-Hy­droxy-5,7,8-trimethyl­chroman-2-one

The title compound, C12H14O3, consists of a chromanone unit with an –OH substituent at the 4-position and methyl substituents on the remaining C atoms of the aromatic ring. The fused pyran­one ring adopts a distorted envelope conformation with the methyl­ene group adjacent to the carbonyl carbon as the flap atom. The crystal structure is stabilized by classical O—H⋯O hydrogen bonds and weak C—H⋯O and C—H⋯π inter­actions, generating a three-dimensional network

3,3′-Diphenyl-1,1′-[2,2′-oxybis(2,1-phenyl­ene)]diurea N,N-dimethyl­formamide disolvate

In the structure of the title compound, C26H22N4O3·2C3H7NO, one of the DMF solvent mol­ecules is disordered over two sets of positions in a 0.5:0.5 ratio. In the 1,1′-[2,2′-oxybis(2,1-phenyl­ene)]bis­(3-phenyl­urea) mol­ecule, the two diphenyl­urea segments are linked via an ether O atom and are inclined at an angle of 53.80 (4)° to one another. In the crystal structure, classical N—H⋯O hydrogen bonds link each mol­ecule to two DMF solvent mol­ecules and these aggregates form columns down a through C—H⋯π inter­actions. Additional C—H⋯O inter­actions link the main mol­ecule and the solvent mol­ecules, forming columns of independent zigzag chains along b

Gel actuators based on polymeric radicals

Low-voltage electrochemical actuation of radical polymer gels has been demonstrated in an organic electrolyte. Polymer gels were prepared by post-modification of active-ester precursor gels with an amine-functionalised radical. A combination of few-layer graphene and multiwall carbon nanotubes gave high conductivity and improved actuation in the gels, with 32% linear actuation. The actuator system showed good stability over at least 10 cycles, showing its promise. The cycle time was several hours due to mass-transport limited transport of ions and solvent into the device

2-Methyl-4,6-bis­(1-methyl­hydrazino)pyrimidine

In the title compound, C7H14N6, the amine groups of the two methyl­hydrazino substituents are orientated in the opposite direction to the methyl substituent at the 2-position of the pyrimidine ring. The mol­ecule is almost planar with only the two amine N atoms lying substanti­ally out of the mean plane of the pyrimidine ring [by 0.1430 (2) and 0.3092 (2) Å]. The H atoms on these amine groups point inwards towards the aromatic ring, such that the lone pair of electrons points outwards from the mol­ecule. Each mol­ecule is linked to two others through N—H⋯N hydrogen bonds between the two amino groups, forming a one-dimensional chain in the [010] direction. Offset face-to-face π–π stacking inter­actions between the pyrimidine rings organize these chains into a two-dimensional array [centroid–centroid distance = 3.789 (2) Å]

2,3,4-Tribromo­thio­phene

In the title compound, C4HBr3S, there are two essentially planar mol­ecules in the asymmetric unit. In the crystal structure, bifurcated C—H⋯Br hydrogen bonds link the mol­ecules into chains. Weak Br⋯Br inter­actions [Br⋯Br = 3.634 (4)–3.691 (4) Å] then lead to undulating sheets in the bc plane

N-Methacryloyl-4-(piperidin-1-yl)-1,8-naphthalimide

In the title compound, C21H20N2O3, the naphthalimide unit is almost planar (r.m.s. deviation for the 15 non-H atoms = 0.059 Å). The carboximide N atom and the five C atoms of the 2-methyl­prop-2-enoyl substituent also lie in a plane (r.m.s. deviation = 0.009 Å), which subtends an angle of 84.34 (7)° to the naphthalamide plane. This orients the =CH2 group of the vinyl fragment towards the naphthalimide rings, giving the mol­ecule an extended configuration. The piperidine ring adopts a chair conformation and there is evidence for some delocalization between the naphthalene and piperidine units, the C—Npip bond length being 1.404 (4) Å. In the crystal structure, π–π contacts with centroid–centroid distances of 3.5351 (18) and 3.7794 (18) Å supported by C—H⋯O hydrogen bonds link adjacent mol­ecules in a head-to-tail fashion, forming dimers. These are further stabilized by other C—H⋯O contacts of varying strength, which stack the mol­ecules down the b axis

N-(1-Acryloyl-2,2,6,6-tetra­methyl­piperidin-4-yl)acryl­amide

The title compound, C15H24N2O2, crystallizes with two unique mol­ecules, (I) and (II), in the asymmetric unit, differing in the orientation of the acryloyl units with respect to the piperidine rings. The acryl­amide units are essentially planar in both mol­ecules (r.m.s. deviations = 0.042 and 0.024 Å, respectively), as are the C3N chains of the acryloyl units. The carbonyl O atoms of the acryloyl systems lie significantly out of these planes, viz. by −0.171 (9) Å for molecule (I) and by 0.33 (1) Å for molecule (II). The acryl­amide and acryloyl planes are inclined at 68.7 (4)° and 59.8 (3)° in the two mol­ecules. The piperidine rings each adopt twist boat conformations. In the crystal, strong N—H⋯O hydrogen bonds link the mol­ecules into zigzag C(4) chains along b. Additional C—H⋯O contacts result in the formation of stacks along a

4,5-Dihydro­cyclo­penta­[b]thio­phen-6-one

The title compound, C7H6OS, crystallizes with two similar mol­ecules, 1 and 2, in the asymmetric unit. Both mol­ecules are essentially planar with r.m.s. deviations of 0.0193 and 0.0107 Å for the planes through the nine non-H atoms of mol­ecules 1 and 2, respectively. The thio­phene and 4,5-dihydro­cyclo­penta­dienone rings are inclined at 2.40 (13)° in 1 and 0.64 (13)° in 2. In the crystal structure π–π [3.6542 (17) Å] and C—H⋯π contacts stack the mol­ecules into columns in an inverse fashion along the b axis. An extensive series of C—H⋯O hydrogen bonds links the columns, generating an extended network structure