Modified synthesis of Ru–Rh heterobimetallic metallacarboranes based on ruthenium exo-nido complexes and not accompanied by exo-nido → closo rearrangement

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Crown compounds for anions: sandwich and half-sandwich complexes of cyclic trimetric perfluoro-o-phenylenemercury with polyhedral closo-[B10H10]2- and closo-[B12H12]2- anions

It has been shown by IR and NMR spectroscopy that cyclic trimeric perfluoro-o-phenylenemercury (o-C6F4-Hg)3 (1) is capable of binding closo-[B10H10]2- and closo-[B12H12]2- anions to form complexes [[(o-C6F4Hg)3](B10-H10)]2- (2), [[(o-C6F4Hg)3]2(B10H10)]2-(3), [[(o-C6F4Hg)3](B12H12)]2- (4), and [[(o-C6F4Hg)3]2(B12H12)]2- (5). According to IR data, the bonding of the [B10H10]2- and [B12H12]2- ions to the macrocycle in these complexes is accomplished through the formation of B-H-Hg bridges. Complexes 2, 3, and 5 have been isolated in analytically pure form and have been characterized by spectroscopic means. X-ray diffraction studies of 3 and 5 have revealed that these compounds have unusual sandwich structures, in which the polyhedral di-anion is located between the planes of two molecules of 1 and is bonded to each of them through two types of B-H-Hg bridges. One type is the simultaneous coordination of a B-H group to all three Hg atoms of the macrocycle. The other type is the coordination of a B-H group to a single Hg atom of the cycle. According to X-ray diffraction data, complex 2 has an analogous but half-sandwich structure. The obtained complexes 2-5 are quite stable; their stability constants in THF/acetone (1:1) at 20 degrees C have been determined as 1.0 x 10(2)Lmol(-1), 2.6 x 10(3)L(2)mol(2), 0.7 x 10(2)Lmol(-1), and 0.98 x 10(3)L(2)mol(-2), respectively.     

Identification of archaeal proteins that affect the exosome function in vitro

Background  

The archaeal exosome is formed by a hexameric RNase PH ring and three RNA binding subunits and has been shown to bind and degrade RNA in vitro. Despite extensive studies on the eukaryotic exosome and on the proteins interacting with this complex, little information is yet available on the identification and function of archaeal exosome regulatory factors.     

Fast generation of random bits based on polarization noises in a semiconductor vertical-cavity laser

It is experimentally demonstrated that intensity fluctuations on a selected polarization in a semi-conductor vertical-cavity laser are an effective source of entropy for fast generation of random bits. The effective generation rate is shown to be from 100 Mbps to 4.5 Gbps at the discretization frequency of 100 MHz, depending on how the random bits are extracted from the polarization noise. The generated sequences of random bits are characterized by low bias and absence of correlation between bits and successfully pass main statistical randomness tests.     

Protonation of (2-formylnorbornadiene)cyclopentadienylrhodium.First example of direct transition metal participation in stabilizing of α-carbocationic centre in O-protonated acyl-substituted π-complexes

Cationic hydroxyallylolefin π-complexes $\text{10a,b}$ whose stabilization of the α-carbocationic centre is achieved with simultaneous participation of both rhodium and oxygen atoms were prepared from the reaction of HCl or F₂POOH with aldehyde $\text{8}$ in ether.     

Bistable vertical cavity laser with periodic pump modulation as a random bits generator

It is experimentally demonstrated that the semiconductor vertical cavity laser with the pump current modulation, operating in the regime of polarization bistability, can be an effective source of true random bits with the rate of generation up to several Mbps, which is determined by the modulation frequency. The generated sequences are characterized by the low bias and low correlations between generated bits.     

Low-lying (K π = 0+) states of gadolinium isotopes

The sd-interacting boson approximation (sd-IBA) and the df-interacting boson approximation (df-IBA) can be related to each other and the states of the interacting boson approximation model can be identified with the fully symmetric states in the sdf interacting boson approximation model. A systematic study of the sdf-IBA model showed that the constructed Hamiltonian can successfully describe the strong octupole correlations in the deformed nuclei. We showed that the interacting boson approximation may account for many of these K ^π ?=?0⁺ states. It was found that the calculated energy spectra of the gadolinium isotopes agree quite well with the experimental data. The observed B(E2) values were also calculated and compared with the experimental data.     

Simple and efficient synthesis of closo-rhoda- and closo-iridacarboranes with π-ligands based on cyclic dienes

Russian Chemical Bulletin -