1-Phenyl-3-{4-[4-(4-undecyl­oxybenzoyl­oxy)phenyl­oxycarbon­yl]phen­yl}triazene 1-oxide

The X-ray crystallographic study of the title compound, C37H41N3O6, at 150 K establishes the N-oxide form of the triazene 1-oxide unit. There is one intra­molecular N—H⋯O hydrogen-bonding inter­action and the crystal packing is stabilized by one N—H⋯O, three C—H⋯O and three C—H⋯π inter­molecular inter­actions. The dihedral angles between pairs of adjacent benzene rings are 14.9 (3), 56.3 (1) and 56.0 (1)

Lithium cobalt(II) pyrophosphate, Li1.86CoP2O7, from synchrotron X-ray powder data

Structure refinement of high-resolution X-ray powder diffraction data of the title compound gave the composition Li1.865CoP2O7, which is also verified by the ICP measurement. Two Co sites exist in the structure: one is a CoO5 square pyramid and the other is a CoO6 octa­hedron. They share edges and are further inter­connected through P2O7 groups, forming a three-dimensional framework, which exhibits different kinds of inter­secting tunnels containing Li cations and could be of great inter­est in Li ion battery chemistry. The structure also exhibits cation disorder with 13.5% Co residing at the lithium (Li1) site. Co seems to have an average oxidation state of 2.135, as obtained from the strutural stochiometry that closely supports the magnetic susceptibility findings

Iron and Manganese Pyrophosphates as Cathodes for Lithium-Ion Batteries

The mixed-metal phases, (Li2Mn1-yFeyP2O7, 0 e y e 1), were synthesized using a “wet method”, and found to form a solid solution in the P21/a space group. Both thermogravimetric analysis and magnetic susceptibility measurements confirm the 2þ oxidation state for both the Mn and Fe. The electrochemical capacity improves as the Fe concentration increases, as do the intensities of the redox peaks of the cyclic voltammogram, indicating higher lithium-ion diffusivity in the iron phase. The two Li þ ions in the three-dimensional tunnel structure of the pyrophosphate phase allows for the cycling of more than one lithium per redox center. Cyclic voltammograms show a second oxidation peak at ∼5 V and ∼5.3 V, indicative of the extraction of the second lithium ion, in agreement with ab initio computation predictions. Thus, electrochemical capacities exceeding 200 Ah/kg may be achieved if a stable electrolyte is found

Novel Synthetic Route to Liquid Crystalline 4,4\u27-Bis(n-Alkoxy) Azoxybenzenes: Spectral Characterisation, Mesogenic Behaviour and Crystal Structure of Two New Members

A simple synthetic method has been developed for the preparation of long-chain 4,4\u27-bis(n-alkoxy)azoxybenzenes by reductive coupling of 4-n-alkoxynitrobenzenes using zinc powder and ammonium chloride in aqueous ethanol medium at ambient temperature. The new method was employed to synthesise known members (n=1-12) of the 4,4\u27-bis(n-alkoxy)azoxybenzene (C n H2n+1OPhN(O)=NPhOC n H2n+1) series and also two hitherto unknown members (n=13-14) of the series. The new compounds were characterised using spectral (IR, UV-visible, 1H NMR and FAB-MS) data. The mesogenic behaviour of both compounds was studied by polarising optical microscopy, differential scanning calorimetry and small-angle X-ray diffraction techniques. The crystal structure of 4,4\u27-bis(n-tetradecyloxy)azoxybenzene was determined using single-crystal X-ray diffraction data. The packing of the molecules in the crystalline state is found to be a precursor to the smectic C phase structure

Structure of Liquid Crystalline 1-Phenyl-3-{4-[4-(4-Octyloxybenzoyloxy) Phenyloxycarbonyl]phenyl}triazene-1-Oxide At Low Temperature

The molecular structure of 1-phenyl-3-{4-[4-(4-octyloxybenzoyloxy)- phenyloxycarbonyl]phenyl}triazene-1-oxide, a member of newly developed liquid crystalline homologous series, has been investigated by crystal X-ray crystallography at low temperature (100K). The title compound crystallizes in the triclinic crystal class in the space group P[image omitted] with cell parameters a=5.766(5), b=12.151(10), c=21.751(17), =79.089(13), =88.646(14), =84.278(14), V=1489(2)3 for Z=2. It establishes the N-oxide form of the triazene-1-oxide moiety. The overall molecule is not planar, the dihedral angles between pairs of adjacent benzene rings are 14.00 (10), 52.36 (07), and 50.57 (07). Intramolecular N-HO hydrogen-bonding is present within the triazene-1-oxide moiety of the title compound. The compound forms inversion dimer via an intermolecular N-HO and an intermolecular C-HO links. The dimers are then linked into chains in a parallel fashion by C-HO hydrogen bonds. The crystal packing is further stabilized by C-H interactions