Introduction of an single nucleodite polymorphism-based "Major Y-chromosome haplogroup typing kit" suitable for predicting the geographical origin of male lineages

The European Consortium "High-throughput analysis of single nucleotide polymorphisms for the forensic identification of persons--SNPforID", has performed a selection of candidate Y-chromosome single nucleotide polymorphisms (SNPs) for making inferences on the geographic origin of an unknown sample. From more than 200 SNPs compiled in the phylogenetic tree published by the Y-Chromosome Consortium, and looking at the population studies previously published, a package of 29 SNPs has been selected for the identification of major population haplogroups. A "Major Y-chromosome haplogroup typing kit" has been developed, which allows the multiplex amplification of all 29 SNPs in a single reaction. Allele genotyping was performed with a single base extension reaction (minisequencing) detected by CE. The validation of the multiplex was performed in a total of 1126 unrelated males distributed among 12 worldwide populations. The approach takes advantage of the specific geographic distribution of the Y-chromosome haplogroups and demonstrates the utility of binary polymorphisms to infer the origin of a male lineage.     

One methylene too far: The solid state structure of the para-sulfonatomethylcalix[4]arene

We report here, the first crystallographic structure of the new water soluble calixarene, para-sulfonatomethylcalix[4]arene. Anchoring a methylene group between the aromatic core of the calixarene and sulfonate groups extended the hydrophobic cavity but led to a more flexible macromolecule allowing formation of hydrogen bonds between vicinal sulfonate groups, causing the groups to point towards the cavity and effectively close it, with S  S distances of 9.7 Å × 7.9 Å. The packing motif consists of bilayers of para-sulfonatomethylcalix[4]arene along both the a and b axis.     

Calix[4]azacrowns: self-assembly and effect of chain length and O-alkylation on their metal ion-binding properties

Both the consequences of 1,3-cyclization of calix[4]arenes by diamide formation, and the effect of 2- and 2,4-alkoxycarbonylmethylation of two 1,3-bridged calix[4]azacrowns on their metal ion-binding capacities have been studied by synthesis of the derivatives in their cone conformation and measurement of the stability constants for their complexation in a range of alkaline earth and transition metal cations. In these two cases, the conformation of the ligand in the solid state has been defined in detail by a crystal structure determination. In the first case, a tubular architecture performing methanol channels is displayed, however, in the second case a zigzag architecture generated by a chloroform network connecting calixarene molecules is present. Speciation in solution appears to be limited to the formation of 1:2 and/or 1:1 and/or 2:1 (M-L) complexes, depending on the system, with values of the stability constants determined by absorption spectroscopy in acetonitrile, lying in the ranges log β₁₂ ca. 10, log β₁₁ ca. 2-5, and log β₂₁ ca. 7-9. There is evidence for selectivity toward Cu(II) and for some unexpected anion effects. None of these ligands appear to be an efficient extractant for the metals as their picrate.     

Solid-state structure by X-ray and 13C CP/MAS NMR of new 6-acetyl-8-bromo-5-O-alkylamino-4,7-dimethylcoumarins

Structural Chemistry - 6-Acetyl-8-bromo-5-[2-(N,N-dimethylamino)ethoxy)-4,7-dimethylcoumarin (1) and 6-acetyl-8-bromo-5-[2-(N,N-diethylamino)ethoxy)-4,7-dimethylcoumarin (2) were synthesized using...     

X-ray structure and 1H NMR assignment of 1-methyl-1,4-dihydro-4-oxo-4′-methylthio-3,3′-diquinolinyl sulfide

The title compound (C₂₀H₁₆N₂OS₂) is orthorhombic, with a = 9.290(2), b = 11.874(3), c = 15.971(4) Å and space group P2₁2₁2₁. Two quinoline moieties are nearly perpendicular to each other (103.5(2)°). Two pairs of heteroatoms in ortho-positions are in very close contact. The 4-oxo and 4-methylthio groups are trans-orientated to the central sulfur bridge. The sulfide preserves a skew conformation. The unusual H-2 proton upfield shift is induced by the ring current effect.     

1-Ethyl-3-methylthio-4-thioxo-1,4-dihydroquinoline or 1-ethyl-3-(methylthio)quinolinium-4-thiolate?

The title compound 1 crystallizes in the monoclinic space group C2/c with a = 16.720(4), b = 8.577(1), c = 15.855(4) Å, and = 98.37(1)°. The thiocarbonyl group C – S bond (1.697(4) Å) is longer than those of typical carbon–sulfur double bonds in thiones. Bond lengths and bond angles in the pyridine ring of the title compound are close to the values found for pyridinium salts.     

Conformational flexibility and pseudosymmetric aggregation in a betainium salt hydrate

Structural Chemistry - The cation of 3-(trimethylammonium)-benzoic acid exhibits a considerable conformational flexibility connected to the orientation of carboxyl group, coupled to the proton...     

Atomically Precise Expansion of Unsaturated Silicon Clusters

Small‐ to medium‐sized clusters occur in various areas of chemistry, for example, as active species of heterogeneous catalysis or as transient intermediates during chemical vapor deposition. The manipulation of stable representatives is mostly limited to the stabilizing ligand periphery, virtually excluding the systematic variation of the property‐determining cluster scaffold. We now report the deliberate expansion of a stable unsaturated silicon cluster from six to seven and finally eight vertices. The consecutive application of lithium/naphthalene as the reducing agent and decamethylsilicocene as the electrophilic source of silicon results in the expansion of the core by precisely one atom with the potential of infinite repetition.