Two salts of di‐p‐toluoyltartaric acid with aromatic amines

The structures of bis­[(R)‐(+)‐1‐phenyl­ethyl­ammonium] (2R,3R)‐(−)‐2,3‐di‐p‐toluoyloxybutane­dioate methanol disolvate monohydrate, 2C₈H₁₂N⁺·C₂₀H₁₆O₈²⁻·2CH₄O·H₂O, (I), and bis­(benzyl­ammonium) (2R,3R)‐(−)‐2,3‐di‐p‐toluoyl­oxy­butane­­dioate dihydrate, 2C₇H₁₀N⁺·C₂₀H₁₆O₈²⁻·2H₂O, (II), exhibit extensive hydrogen bonding, with (N—)H⋯O and (O—)H⋯O distances in the ranges 2.716 (2)–2.929 (3) and 2.687 (2)–2.767 (2) Å, respectively, in (I), and 2.673 (2)–2.888 (2) and 2.785 (2)–2.931 (2) Å, respectively, in (II). The amine groups are protonated and the carboxyl­ate groups of the tartrate anions are fully deprotonated. The conformation of the toluoyltartrate anion and its mol­ecular parameters are similar in both structures.     

A `tetrameric' 3,4‐di‐p‐tolyl‐1,2,5‐oxadiborole derivative

In the title compound, 1,1,6a,7,9a,10‐hexa­chloro‐2,3,5,6,8,9,11,12‐octa‐p‐tolyl‐1,6a,9a,12a‐tetraborata‐3a,4a,7,10‐tetrabora‐4a¹,6b,9b,12b‐tetraoxonia‐4‐oxatetra­cyclo­penta­[1,2‐a:2,1,5‐de:1,2‐g:1,2‐i]­naphthalene di­chloro­methane pentasolvate, C₆₄H₅₆B₈Cl₆O₅·5CH₂Cl₂, two condensed oxadiborole rings are attached to two further oxadiborole rings in a type of donor–acceptor bonding, thus forming a ten‐membered alternating (B—O)₅ naphthalene‐like arrangement as the central building block.     

Bis(4‐aminopyridinium) hexachloridostannate(IV) and bis(p‐toluidinium) hexachloridostannate(IV)

The crystal structures of the two organic–inorganic hybrids bis(4‐aminopyridinium) hexachloridostannate(IV), (C₅H₇N₂)₂[SnCl₆], and bis(p‐toluidinium) hexachloridostannate(IV), (C₇H₁₀N)₂[SnCl₆], differ in the way their cations pack in the layered structures. The Sn atom in the 4‐aminopyridinium compound lies on an inversion centre.     

p‐Chloro‐, p‐bromo‐ and two polymorphs of p‐iodo­aceto­phenone

The title p‐haloaceto­phenones, C₈H₇XO (X = Cl, Br and I), have different packing modes. The chloro compound contains H⋯O and H⋯Cl contacts, but no Cl⋯O contacts. The bromo compound and one polymorph (A) of the iodo compound are isomorphous, with significant X⋯O contacts [Br⋯O = 3.320 (4) Å and I⋯O = 3.374 (5) Å]. In the other polymorph (B) of the iodo compound, the I⋯O distance is 3.082 (4) Å. Both polymorphs contain C—H⋯π contacts; these contacts are shorter in A than in B.     

Halogenido and Pseudohalogenido Complexes of (2,3,7,8,12,13,17,18‐Octaethyl‐5,15‐di‐p‐tolylcorrolato)manganese(IV)

A set of porphyrinoid manganese(IV) complexes with the 2,3,7,8,12,13,17,18‐octaethyl‐5,15‐di‐p‐tolylcorrolato ligand [(oedtc)Mn^IVX] (X = Cl, Br, I) was prepared by oxidation of a manganese(III) precursor. The most unexpected complex in this series, [(oedtc)Mn^IVI], was found to display significant thermal stability despite the unusual Mn^IV‐I bond and could be investigated by X‐ray diffraction. Attempted ligand exchange reactions of the chlorido derivative with the pseudohalide anions cyanide, azide, cyanate and thiocyanate yielded the desired [(oedtc)Mn^IVX] complex only as the isothiocyanate derivative while for the other species the reduction to manganese(III) was observed.     

l‐Argininamidium bis­(hydrogen­squarate)

Cations and anions of the title compound {systematic name: 1‐[4‐(amino­carbonyl)butyl]guanidinium bis­(hydrogen­squarate)}, C₆H₁₇N₅O²⁺·2C₄HO₄⁻, are connected into a three‐dimensional network by inter­molecular N—H⋯O hydrogen bonds between the l ‐argininamidium ammonium, amide and guanidinium functions and the hydrogensquarate carbonyl O atoms. The independent hydrogensquarate monoanions are linked into dimers by pairs of O—H⋯O′ hydrogen bonds.     

2‐Arylimino(diferrocenyl)‐ and (di‐p‐anisyl)dihydropyrimidines: Novel Synthesis,Structures, and Electrochemistry

2,3‐Differocenyl‐ and 2,3‐dianisyl‐1‐methylsulfanylcyclopropenilium iodides react with 1,3‐diphenyl‐ and 1,3‐di‐o‐tolylguanidine to give 1‐aryl‐2‐arylimino‐5,6‐ ( 5a , 5b ) and ‐4,5‐diferrocenyl‐1,2‐dihydropyrimidines ( 6a , 6b ) (～ 2:1) and, respectively, 5,6‐ and 4,5‐dianisyl‐3‐phenyl‐2‐phenylimino‐1,2‐dihydropyrimidines (～ 2:1). Their structures were established based on the spectroscopic data and X‐ray diffraction analysis of 5,6‐diferrocenyl‐1‐(o‐tolyl)‐2‐(o‐tolyl)imino‐ and 4,5‐diferrocenyl‐1‐phenyl‐2‐phenylimino‐1,2‐dihydropyrimidines ( 5b and 6a , respectively). Electrochemical behavior of compounds 5b, 6b, and 5a+6a were investigated using experiments of cyclic voltammetry and chronoamperometry. For all the compounds, two electrochemical processes ( I , II ), attributed to the oxidations of the ferrocenes moieties were observed. The values of ΔE^0′ ( II‐I ) and comproportionation constant K_com are also reported. Additionally, an electrochemical oxidation with a fast coupled chemical reaction related to the pyrimide ring was also detected.     

Dual Self‐Assembling Polycondensation of p‐Acetoxybenzoic Acid and p‐Acetamidobenzoic Acid

The dual self‐assembling polycondensation of p‐acetoxybenzoic acid (ABA) and p‐acetamidobenzoic acid in Therm S 800 was examined at 300 °C. Needle‐like crystals and lath‐like crystals were formed simultaneously through reaction‐induced crystallization of oligomers at a molar ratio of 30–50 mol‐% ABA in the feed. The needle‐like crystals comprised more p‐oxybenzoyl units, whereas the lath‐like ones contained higher amounts of p‐benzamide moieties.

     

Relativistic and Non‐Relativistic Electronic Molecular‐Structure Calculations for Dimers of 4p‐, 5p‐, and 6p‐Block Elements

We report results of non‐relativistic and two‐component relativistic single‐reference coupled‐cluster with single and double and perturbative triple excitations [CCSD(T)] treatments for the 4p‐block dimers Ga₂ to Br₂, the 5p‐block dimers In₂ to I₂, and their atoms. Extended basis sets up to pentuple zeta are employed and energies extrapolated to the complete basis‐set limit. Relativistic and non‐relativistic results for the dissociation energy D_e are in close agreement with each other and previously published data, provided non‐relativistic or scalar‐relativistic results are corrected for spin–orbit contributions taken from the literature. An exception is Te₂ where theoretical results scatter by 0.085 eV. By virtue of this agreement it is unexpected that comparison with the experimental D₀ or D_e dissociation energies (zero‐point vibrational effects are negligible in this context) reveal errors larger than 0.1 eV for Ga₂, Ge₂, and Sb₂. Only relativistic treatments are presented for the 6p‐block cases Tl₂ to At₂. Sufficient agreement with experimental data is found only for Pb₂ and Bi₂, the deviation of the computed and experimental D₀ values for Po₂ is again larger than 0.1 eV. Deviations of 0.1 eV between the computed and experimental D₀ values are a major reason for concern and call for additional investigations in both fields to clarify the situation.     

Copper(II) succinate complexes with 1,2‐di‐4‐pyridylethane and 1,3‐di‐4‐pyridylpropane

The compounds poly[di‐μ₄‐succinato‐μ₂‐1,2‐di‐4‐pyridylethane‐dicopper(II)], [Cu₂(C₄H₄O₄)₂(C₁₂H₁₂N₂)]_n, (I), and poly[di‐μ₄‐succinato‐μ₂‐1,3‐di‐4‐pyridylpropane‐dicopper(II)], [Cu₂(C₄H₄O₄)₂(C₁₃H₁₄N₂)]_n, (II), exhibit polymeric structures with the dicopper units doubly bridged by bis‐bidentate succinate groups and crosslinked by the separator bis(pyridyl) molecules. In (I), the molecule exhibits a centre of inversion located midway between the core Cu‐dimer atoms and another that relates half of the bis(pyridyl)ethane ligand to the other half. Compound (II) has a similar molecular packing but with a doubled lattice constant and noncentrosymmetric core units. An antiferromagnetic interaction due to the dinuclear copper units was deduced from magnetic subsceptibility measurements, and spin triplet signals were detected in the electron paramagnetic resonance spectra for both compounds.     

Self‐assembly of di‐ and triblock PEG‐pentavaline amphiphiles

Nanoparticles formed from amphiphilic block copolymers can be used as drug delivery vehicles for hydrophilic therapeutics. Poly(ethylene glycol) (PEG)‐peptide copolymers were investigated for their self‐assembling properties and as consequent potential delivery systems. Mono‐ and dihydroxy PEGs were functionalized with a pentavaline sequence bearing Fmoc end groups. The molecular weight of the PEG component was varied to evaluate copolymer size and block number. These di‐ and tri‐block copolymers readily self‐assemble in aqueous solution with critical aggregation concentrations (CACs) of 0.46–16.29 μM. At concentrations above the CAC, copolymer solutions form spherical assemblies. Dynamic light scattering studies indicate these aggregates have a broad size distribution, with average diameters between 33 and 127 nm. The copolymers are comprised β‐conformations that are stable up to 80 °C, as observed by circular dichroism. This peptide secondary structure is retained in solutions up to 50% MeOH as well. The triblock copolymers proved to be the most stable, with copolymers synthesized from 10 kDa PEG having the most stable particles. Loading of carboxyfluorescein at 2–5 mol % shows that these copolymers have the potential to encapsulate hydrophilic drugs for delivery applications. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

l‐Kynureninium sulfate dihydrate

In the structure of the title compound, 2‐(3‐ammonio‐3‐carboxy­propanoyl)‐1‐anilinium sulfate dihydrate, C₁₀H₁₄N₂O₃²⁺·SO₄^2?·2H₂O, the two amino groups are proton­ated. The mol­ecule has a trans planar zigzag carbon‐skeletal conformation elongated nearly in the benzene ring plane. The two amino and the carboxyl groups are located on the same side of the mol­ecule. The crystal structure is stabilized by intermolecular hydrogen bonds involving the water mol­ecules and the sulfate ion.     

A novel three‐dimensional supra­molecular coordination polymer: poly­[[di­aqua­dicadmium(II)‐di‐μ2‐4,4′‐bipyridyl‐di‐μ2‐2‐sulfonatobenzoato] dihydrate]

The hydro­thermal reaction of Cd(CH₃COO)₂·2H₂O, 4,4′‐bipyridyl and 2‐sulfo­benzoic acid produced the title compound, {[Cd₂(C₇H₄O₅S)₂(C₁₀H₈N₂)₂(H₂O)₂]·2H₂O}_n, which forms a two‐dimensional coordination polymer, the sheets of which are linked via hydrogen bonds. Two different types of Cd atoms are present, one lying on a twofold rotation axis and the other on a centre of inversion. Similarly, there are two types of bipyridyl ligand present, one lying across a twofold rotation axis and the other across a centre of inversion.     

l‐Phenyl­alanyl‐l‐alanine dihydrate

A new type of molecular arrangement for dipeptides is observed in the crystal structure of l ‐phenyl­alanyl‐l ‐alanine dihydrate, C₁₂H₁₆N₂O₃·2H₂O. Two l ‐Phe and two l ‐Ala side chains aggregate into large hydro­phobic columns within a three‐dimensional hydrogen‐bond network.     

p‐Nitro­phenyl isocyanide

Achiral p‐nitro­phenyl isocyanide, C₇H₄N₂O₂, crystallizes in the orthorhombic chiral space group P2₁2₁2₁. Attractive intermolecular interactions between the nitro O atoms and both aromatic H and nitro N atoms of neighbouring mol­ecules are observed. The O⋯N interaction is surprisingly strong [N⋯O = 2.869 (2) Å] compared with other aromatic nitro compounds.     

Bis­(O,O′‐di‐p‐tolyldithiophosphato‐S,S′)(1,10‐phenanthroline‐N,N′)nickel(II)

The title coordination complex, [Ni(C₁₄H₁₄O₂PS₂)₂(C₁₂H₈N₂)] or [Ni(pMePh‐dtp)₂(phen)] (phen is 1,10‐phenanthroline; dtp is di­aryl­di­thio­phosphate), has a non‐crystallographic twofold axis of symmetry through the Ni atom and the phen moiety. Two O,O‐di‐p‐tolyl­di­thio­phosphate (dtp) ions act as bidentate ligands. The central metal atom is coordinated by four S atoms from two dtp groups and two N atoms from the phen ligand. The title compound displays distorted octahedral geometry around the central Ni atom.     

l‐Isoleucyl‐l‐phenyl­alanine dihydrate

The structure of the title compound, C₁₅H₂₂N₂O₃·2H₂O, was derived from data collected on a very thin twinned needle. The peptide mol­ecule is in a rare conformation normally associated with hydro­phobic dipeptides that form nanotubes. Nevertheless, the present structure is divided into hydro­phobic and hydro­philic layers.     

Unusual tosyl transfer solvolysis reaction to 3‐n‐butyl‐4‐methyl‐5,5‐di‐p‐toluenesulfonyl‐ 3 ‐pyrrolin‐2‐one

The title compound ( 1 ) was isolated in 20‐30% recovery following solvolysis of a mixture of 5‐bromo‐3‐n‐butyl‐4‐methyl‐2‐p‐toluenesulfonylpyrrole ( 4b ) and 5‐bromo‐4‐n‐butyl‐3‐methyl‐2‐p‐toluenesulfonyl‐pyrrole ( 4a ) in trifluoroacetic acid and water, a reaction designed to produce 5‐p‐toluenesulfonyl‐3‐pyrrolin‐2‐ones, e.g., 5a and 5b .     

The low‐temperature phase of di‐tert‐butylsilanediol

The crystal structure of di‐tert‐butyl­silanediol, C₈H₂₀O₂Si, has a reversible phase transition at 211 (2) K. The orthorhombic high‐temperature structure has space group Ibam, with Z′ = , and shows a disordered hydrogen‐bonding system. The low‐temperature structure, determined at 143 (2) K, has a twinned monoclinic cell, with space group C2/c and Z′ = 2, and shows an ordered hydrogen‐bonding system.