Synthesis, crystal structure and magnetic properties of an alternating manganese chain

A new 1D complex has been prepared and characterized. X-ray single crystal structure confirms that the Mn(II) ions assemble in alternating chains with Mn-Mn distances of 3.8432(13) and 4.4428(14) Å. A 3D network of hydrogen bonds links the chains together. The temperature dependence of the magnetic susceptibility reveals that this compound undergoes a magnetic transition and exhibits an antiferromagnetic interaction in the low-temperature phase with two alternating exchange interactions of -2.32(1) and -5.55(1) cm-1.http://www.sciencedirect.com/science/article/B6WM2-4JKC5PW-3/1/57fbdb3ac410627d046c6e4fdf2f0e3

(Benzoato-κ2 O,O′)(quinoline-2-carboxyl­ato-κ2 N,O)(quinoline-2-carboxylic acid-κ2 N,O)manganese(II)

The crystal structure of the title compound, [Mn(C7H5O2)(C10H6NO2)(C10H7NO2)], contains manganese(II) ions six-coordinated in a distorted octa­hedral environment. The equatorial plane is occupied by four O atoms, two from the carboxyl­ate group of the benzoate ion, the other two from carboxyl­ate/carboxyl groups of the quinaldate/quinaldic acid mol­ecules. The axial positions are occupied by the N atoms of the quinoline ring systems. The metal ion lies on a twofold rotation axis that bisects the benzoate ligand; the quinaldate and quinaldic acid ligands are therefore equivalent by symmetry, and the carboxylate/carboxyl groups are disordered. The complexes are joined together by hydrogen bonds between the carboxyl­ate/carboxyl groups of adjacent quinaldate/quinaldic acid mol­ecules, forming zigzag chains that run along the c axis

Ethyl 3,5-dimethyl-1H-pyrrole-2-carboxyl­ate

In the title compound, C9H13NO2, there are two independent mol­ecules per asymmetric unit. The mol­ecules are very similar and almost planar, with the ethoxy­carbonyl group anti to the pyrrole N atom. The two independent mol­ecules are joined into dimeric units by strong hydrogen bonds between NH groups and carbonyl O atoms

Bis[(2-quinol­yl)methane­diol-κ2 N,O](sulfato-κO)copper(II) dihydrate

In the title compound, [Cu(SO4)(C10H9NO2)2]·2H2O, the CuII ion is chelated by two (2-quinol­yl)methane­diol ligands and coordinated by a monodentate sulfate ligand in a distorted trigonal–bipyramidal environment, with O atoms occupying the equatorial sites and N atoms in the axial sites. The dihedral angle between the two essentially planar quinoline ring systems is 45.02 (9)°. In the crystal structure, an extensive O—H⋯O hydrogen-bonding network forms layers parallel to the ab plane

(Benzoato-κ2 O,O′)(quinoline-2-carboxyl­ato-κ2 N,O)(quinoline-2-carboxylic acid-κ2 N,O)copper(II)

The crystal structure of the title compound, [Cu(C10H6NO2)(C7H5O2)(C10H7NO2)], contains copper(II) ions five-coordinated in a distorted trigonal-bipyramidal environment. The equatorial plane is occupied by three O atoms, one from the carboxyl­ate group of the benzoate ion considered as occupying a single coordination site, the other two from two carboxyl­ate groups of the quinaldic acid and quinaldate ligands. The axial positions are occupied by the N atoms of the quinoline ring system. The metal ion lies on a twofold axis that bisects the benzoate ion. The quinaldate and quinaldic acid ligands are equivalent by symmetry, and the carboxyl­ate/carboxyl groups are disordered. The disordered H atom is shared between the carboxyl­ate groups of adjacent quinaldic acid mol­ecules. Such hydrogen bonds delineate zigzag chains that run along the c axis. The structure is very similar to that of the MnII analog

(R,R)-N-phenyl-3,4-bis(diphenylphosphino)pyrrolidine: an N-aryl pyrrolidine ligand for enantioselective transfer hydrogenation

The N-aryl pyrrolidine diphosphine (R,R)-N-phenyl-3,4-bis(diphenylphosphino)pyrrolidine was obtained from natural tartaric acid. Contrary to our preliminary expectations, this new chiral ligand proved to be less selective than the corresponding N-benzyl pyrrolidine diphosphine. An attempted explanation of the observed behaviour based on the stereochemistry of the ligand as shown by X-ray crystallography is presented.http://www.sciencedirect.com/science/article/B6TGM-42G6XGY-8/1/25fa9c4e0f48edebc992db1e0b302bf

2,2′,5,5′-Tetra­methyl-1,1′-(hexane-1,6-di­yl)di-1H-pyrrole

The mol­ecule of the title compound, C18H28N2, composed of two 2,5-dimethyl­pyrrole groups linked by a hexane chain, lies across a crystallographic inversion centre. The mean plane of the pyrrole ring is almost perpendicular to the mean plane of the central chain, making a dihedral angle of 89.09 (8)°. The crystal structure is stabilized by inter­molecular C—H⋯π inter­actions

(R)-2′-Benz­yloxy-5,5′,6,6′,7,7′,8,8′-octa­hydro-1,1′-binaphthyl-2-ol

The mol­ecules of the title compound, C27H28O2, exhibit axial chirality. The planes of the aromatic rings of the tetra­lin ring systems make an angle of 85.72 (11)°. The non-aromatic rings adopt distorted half-chair conformations. In one of them, two C atoms of the four-atom aliphatic chain are disordered over two sites in a 0.75 (2):0.25 (2) ratio. The substituent phenyl ring is also disordered over two positions in a 0.59 (3):0.41 (3) ratio. There are no conventional hydrogen bonds joining the mol­ecules

6β-Chloro-5α-hydr­oxy-20-oxopregnan-3β-yl acetate

The title steroid, C23H35ClO4, is a pregnane derivative prepared by ring opening of the corresponding 5α,6α-ep­oxy steroid with BiCl3. There are two symmetry-independent mol­ecules in the asymmetric unit that show no significant differences concerning bond lengths and angles. The conformation of the six-membered rings in both mol­ecules is close to a chair form, while the five-membered ring adopts an envelope conformation. All rings in both mol­ecules are trans-fused. The mol­ecules are held together by an extensive O—H⋯O hydrogen-bonding network

Monitoring frequency influences the analysis of resting behaviour in a forest carnivore

Resting sites are key structures for many mammalian species, which can affect reproduction, survival, population density, and even species persistence in human-modified landscapes. As a consequence, an increasing number of studies has estimated patterns of resting site use by mammals, as well as the processes underlying these patterns, though the impact of sampling design on such estimates remain poorly understood. Here we address this issue empirically, based on data from 21 common genets radiotracked during 28 months in Mediterranean forest landscapes. Daily radiotracking data was thinned to simulate every other day and weekly monitoring frequencies, and then used to evaluate the impact of sampling regime on estimates of resting site use. Results showed that lower monitoring frequencies were associated with major underestimates of the average number of resting sites per animal, and of site reuse rates and sharing frequency, though no effect was detected on the percentage use of resting site types. Monitoring frequency also had a major impact on estimates of environmental effects on resting site selection, with decreasing monitoring frequencies resulting in higher model uncertainty and reduced power to identify significant explanatory variables. Our results suggest that variation in monitoring frequency may have had a strong impact on intra- and interspecific differences in resting site use patterns detected in previous studies. Given the errors and uncertainties associated with low monitoring frequencies, we recommend that daily or at least every other day monitoring should be used whenever possible in studies estimating resting site use patterns by mammals