Gauche and staggered forms of diethylamine in solvates of 1,5-dichloro-cis-9,10-diethynyl-9,10-dihydroanthracene-9,10-diol. A case of conformational pseudopolymorphism?

Diethylamine has been trapped in its less stable gauche conformation in a solvate of the title diol; the staggered conformation, which is ca. 4 kJ mol-1 more stable, is found in another solvate of the same host

Crystal engineering in the aminophenols. Novel carborundum network in a supramolecular homologous series

Molecular complexes of 4-(4-aminophenoxy)aniline with a series of diphenols are structurally homologous and adopt the carborundum III topology, which is an unprecedented network for organic solids

Uncooled tunneling infrared sensor

An uncooled infrared tunneling sensor in which the only moving part is a diaphragm which is deflected into contact with a micromachined silicon tip electrode prepared by a novel lithographic process. Similarly prepared deflection electrodes employ electrostatic force to control the deflection of a silicon nitride, flat diaphragm membrane. The diaphragm exhibits a high resonant frequency which reduces the sensor's sensitivity to vibration. A high bandwidth feedback circuit controls the tunneling current by adjusting the deflection voltage to maintain a constant deflection of the membrane which would otherwise change deflection depending upon incident infrared radiation. The resulting infrared sensor will meet or exceed the performance of all other broadband, uncooled, infrared sensors and can be miniaturized to pixel dimensions smaller than 100 .mu.m. The technology is readily implemented as a small-format linear array suitable for commercial and spacecraft applications

Seeking structural repetitivity in systems with interaction interference: crystal engineering in the gem-alkynol family

Synthon repetitivity has been demonstrated in a pair of gem-alkynols, despite the high degree of interaction interference typical of this family of compounds

Design of an SHG-active crystal, 4-iodo-4'-nitrobiphenyl: therole of supramolecular synthons

The crystal structure of 4-iodo-4'-nitrobiphenyl has been determined with packing calculations and the presence of polar and parallel iodo···nitro supramolecular synthons leads to non-centrosymmetry and measurable SHG activity

Sandwich and half-sandwich metal complexes derived from cross-conjugated 3-methylene-penta-1,4-diynes

The cross-conjugated ethynyl–vinylidene [Ph2CvC(CuCH){C(H)vCRu(PPh3)2Cp}]PF6 ([4a]PF6), and [FcC (H)vC(CuCH){C(H)vCRu(PPh3)2Cp}]PF6 ([4b]PF6), and ethynyl–alkynyl Ph2CvC(CuCH){CuCRu(PPh3)2Cp} (5a), and FcC(H)vC(CuCH){CuCRu(PPh3)2Cp} (5b) compounds (Cp = η5-cyclopentadienyl) have been prepared from reactions of the known 3-methylene-penta-1,4-diynes Ph2CvC(CuCH)2 (3a) and [FcCHvC(CuCH)2] (3b) with [RuCl(PPh3)2Cp]. The compounds derived from 3b incorporating the more electron-rich alkene proved to be unstable during work-up, and attempts to prepare bis(ruthenium) complexes from 3a and 3b or from transmetallation reactions of the bis(alkynylgold) complex FcCHvC(CuCAuPPh3)2 (7) with RuCl(PPh3)2Cp were unsuccessful. The related bis- and tris(ferrocenyl) derivatives Ph2CvC(CuCFc)2 (6a) and FcCHvC(CuCFc)2 (6b) were more readily obtained from Pd(II)/Cu(I) catalysed cross-coupling reactions of FcCuCH with the 1,1-dibromo vinyl complexes PhCvCBr2 (1a) and FcC(H)vCBr2 (1b). Cyclic voltammetry of 6a and 6b using n-Bu4N[PF6] as the supporting electrolyte shows broad, overlapping waves arising from the sequential oxidation of the ferrocenyl moieties in electronically and chemically similar environments. Electrostatic effects between the ferrocenyl moieties are enhanced in solutions of the weakly ion-pairing electrolyte n-Bu4N[B{C6H3(CF3)2-3,5}4], leading to better resolution of the individual electrochemical processes. The comparative IR spectroelectrochemical response of 6a and 6b suggest the vinyl ferrocene moiety in 6b undergoes oxidation before the ethynyl ferrocene fragments. There is no evidence of electronic coupling between the metallocene moieties and [6a]+, [6b]n+ (n = 1, 2) are best described as Class I mixed-valence compounds

When is a polymorph not a polymorph? Helical trimeric O-H···O synthons in trans-1,4-diethynylcyclohexane-1,4-diol

Two polymorphs (A and B) of trans-1,4-diethynylcyclohexane-1,4-diol represent a unique example of the simultaneous occurrence of both conformational polymorphism and conformational isomorphism, while a pseudopolymorphic monohydrate is closely related

The 4-(3-chloro-4-methyl­phen­yl)-1,2,3,5-dithia­diazol-3-yl radical

The asymmetric unit of the title compound, C8H6ClN2S2, comprises two mol­ecules forming a dimer via π–π stacking inter­actions [centroid–centroid distance = 3.634 (10) Å] and intra­dimer S⋯S contacts [3.012 (4) and 3.158 (4) Å] between the two mol­ecules in a cis-antarafacial arrangement