5-[4'-(2,2,5,5-Tetramethyl-3-pyrroline-1-oxyl-3-carbonyl)biphenyl-4-ylethynyl]-2,3,7,8,12,13,17,18-octaethylporphyrinato}copper(II) benzene solvate : corrigendum

In the paper by Bolte [Acta Cryst. (2006), E62, m1609-m1610], the chemical name in the title and the chemical diagram are incorrect. The correct title is {5-[4'-(2,2,5,5-Tetramethyl-3-pyrroline-1-oxyl-3-carbonyloxy)biphenyl-4-ylethynyl]-2,3,7,8,12,13,17,18-octaethylporphyrinato}copper(II) benzene solvate' and the correct diagram is given below

Intra- and intermolecular proton transfer in 2,6-diaminopyridinium 4-hydroxypyridin-1-ium-2,6-dicarboxylate

Chelidamic acid (4-hydroxypyridine-2,6-dicarboxylic acid) and 2,6-diaminopyridine react to form the title salt, C5H8N3+·C7H4NO5-; there are two formula units in the asymmetric unit. The pyridine N atom of 2,6-diaminopyridine is protonated whereas chelidamic acid is deprotonated at both carboxylate groups but protonated at the N atom; the reaction involves intra- and intermolecular proton transfer. In the crystal, each 2,6-diaminopyridinium cation participates in five strong N-H...O hydrogen bonds (including one bifurcated hydrogen bond). The crystal structure also features strong O-H...O hydrogen bonds between the chelidamate anions, leading to chains along the a axis

Amiloride hydro­chloride methanol disolvate

In the crystal of the title compound [systematic name: 2-(3,5-diamino-6-chloro­pyrazin-2-ylcarbon­yl)guanidinium chloride methanol disolvate], C6H9ClN7O+·Cl-·2CH3OH , the components are connected by N—H ... N, N—H ... Cl, N—H ... O, O—H ... Cl and O—H ... O hydrogen bonds into a three-dimensional network. The dihedral angle between the aromatic ring and the guanidine residue is 6.0 (2)°

(Biphenyl-2-yl)bromidobis(2-methyltetrahydrofuran-[kappa]O)magnesium(II)

In the title Grignard reagent, [MgBr(C12H9)(C5H10O)2], the Mg centre adopts a distorted tetrahedral MgCO2Br arrangement. The dihedral angle between the two aromatic rings of the biphenyl residue is 44.00 (14)°. Each molecule incorporates one R- and one S-configured 2-methyltetrahydrofuran molecule. Key indicators: single-crystal X-ray study; T = 173 K; mean σ(C–C) = 0.007 Å; R factor = 0.045; wR factor = 0.108; data-to-parameter ratio = 17.4

Synthesis and Crystal Structure of 1-(3-fluorophenyl)-3-(3,4,5-trimethoxybenzoyl)thiourea

The title thiourea was synthesized by reaction of 3,4,5-trimethoxybenzoyl isothiocyante with 3-fluoroaniline. The 3,4,5-trimethoxybenzoyl isothiocyante was produced in situ by reaction of 3,4,5-trimethoxybenzoyl chloride with ammonium thiocyanate in dry acetonitrile. The structure was confirmed by the spectroscopic, elemental analysis and single crystal X-ray diffraction data. It crystallizes in the monoclinic space group P21/c with unit cell dimensions a = 13.0966(9), b = 16.6460(13), c = 7.8448(5), β = 106.721(5)°, V 1637.9(2) ų, Z = 4

(1R,2S)-Methyl 1-(4-chloro-phen-yl)-3-oxo-1,2,3,4-tetra-hydro-cyclo-penta-[b]indole-2-carboxyl-ate 0.2-hydrate

The title compound, C(19)H(14)ClNO(3)·0.2H(2)O, crystallizes with five mol-ecules and a disordered water mol-ecule in the asymmetric unit. Four of the five mol-ecules form hydrogen-bonded dimers via N-H⋯O hydrogen bonds towards another symmetry-independent mol-ecule, whereas the fifth mol-ecule forms a hydrogen-bonded dimer with its symmetry equivalent, also via N-H⋯O hydrogen bonds. The dihedral angle between the planes of the fused benzene ring and the five-membered ring to which it is attached is 79.45 (13), 49.00 (15), 72.49 (16), 81.91 (18) and 76.38 (16)° for the five mol-ecules in the asymmetric unit

Dichloridobis(di-tert-butylmethylphosphine oxide-[kappa]O)diphenyltin(IV)

The complete molecule of the title compound, [Sn(C6H5)2Cl2(C9H21OP)2], is generated by crystallographic inversion symmetry, the Sn atom is located on a special position of site symmetry \overline{1}. The Sn atom adopts an all-trans SnC2O2Cl2 octahedral geometry. As a consequence of the bulky substituents at the O atom, the P-O-Sn bond angle is 163.9 (3)°. Key indicators: single-crystal X-ray study; T = 173 K; mean σ(C–C) = 0.012 Å; R factor = 0.058; wR factor = 0.099; data-to-parameter ratio = 18.6

(18-Crown-6-[kappa]6O)(pyrazolato-[kappa]2N,N')-potassium(I)

The asymmetric unit of the title compound, [K(C3H3N2)(C12H24O6)], is composed of a potassium cation bonded to the six O atoms of a crown ether molecule and the two N atoms of a pyrazolate anion. The K...O distances range from 2.8416 (8) to 3.0025 (8) Å, and the two K...N distances are 2.7441 (11) and 2.7654 (11) Å. The K cation is displaced by 0.8437 (4) Å from the best plane through the six O atoms. The latter plane is almost perpendicular to the plane of the pyrazolate ring [dihedral angle 83.93 (3)°]. Key indicators: single-crystal X-ray study; T = 173 K; mean σ(C–C) = 0.002 A°; R factor = 0.026; wR factor = 0.066; data-to-parameter ratio = 16.5

Probing The Lower Mass Limit For Supernova Progenitors And The High-Mass End Of The Initial-Final Mass Relation From White Dwarfs In The Open Cluster M35 (NGC 2168)

We present a photometric and spectroscopic study of the white dwarf (WD) population of the populous, intermediate-age open cluster M35 (NGC 2168); this study expands upon our previous study of the WDs in this cluster. We spectroscopically confirm 14 WDs in the field of the cluster: 12 DAs, 1 hot DQ, and 1 db star. For each DA, we determine the WD mass and cooling age, from which we derive each star's progenitor mass. These data are then added to the empirical initial-final mass relation (IFMR), where the M35 WDs contribute significantly to the high-mass end of the relation. The resulting points are consistent with previously published linear fits to the IFMR, modulo moderate systematics introduced by the uncertainty in the star cluster age. Based on this cluster alone, the observational lower limit on the maximum mass of WD progenitors is found to be similar to 5.1M(circle dot) - 5.2M(circle dot) at the 95% confidence level; including data from other young open clusters raises this limit to as high as 7.1M(circle dot), depending on the cluster membership of three massive WDs and the core composition of the most massive WDs. We find that the apparent distance modulus and extinction derived solely from the cluster WDs ((m-M)(V) = 10.45 +/- 0.08 and E(B-V) = 0.185 +/- 0.010, respectively) is fully consistent with that derived from main-sequence fitting techniques. Four M35 WDs may be massive enough to have oxygen - neon cores; the assumed core composition does not significantly affect the empirical IFMR. Finally, the two non-DA WDs in M35 are photometrically consistent with cluster membership; further analysis is required to determine their memberships.NSF AST-0397492, AST-0602288Astronom

Di-μ-bromido-bis-[(diethyl ether-κO)(2,4,6-trimethylphenyl)magnesium] : the mesityl Grignard reagent

The crystal structure of the title compound, [Mg2Br2(C9H11)2(C4H10O)2], features a centrosymmetric two-centre magnesium complex with half a mol-ecule in the asymmetric unit. The Mg atom is in a considerably distorted Br2CO coordination. Bond lengths and angles are comparable with already published values. The crystal packing is stabilized by C-H⋯π inter-actions linking the complexes into sheets parallel to (0-11)