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New J. Chem., 2017, 41, 316-325

Elena V. Andrusenko, Evgeniy V. Kabin, Alexander S. Novikov, Nadezhda A. Bokach, Galina L. Starova and Vadim Yu. Kukushkin

“Metal-mediated generation of triazapentadienate-terminated di- and trinuclear μ2-pyrazolate NiII species and control of their nuclearity”

New J. Chem., 2017, 41, 316-325
DOI:10.1039/C6NJ02962K
источник: http://pubs.rsc.org/

1,3,5-Triazapentadienate-terminated di- and trinuclear nickel(II) complexes featuring bridging azolate ligands, [Ni2(μ2-azolate)2(TAP)2] (TAP = H[N with combining low line][double bond, length as m-dash]C(OMe)NC(OMe)[double bond, length as m-dash][N with combining low line]H; azole = 3,5-Me2pyrazole 2, 3,5-Ph2pyrazole 3) and [Ni3(μ2-azolate)4(TAP)2] (azole = 3,5-Me2pyrazole 4, indazole 5), were obtained from systems Ni2+/NCNR2/azole systems in MeOH. The terminal TAP ligands in the [Ni2(μ2-azolate)2(TAP)2] and [Ni3(μ2-azolate)4(TAP)2] species originate from the previously unreported cascade NiII-mediated and chelation-driven reaction between cyanamides and methanol. The oligomeric species and also [Ni(TAP)2] (1) are subject to interconversions that depend on the reactants involved and the reaction conditions. The control of the nuclearity of the complexes can be achieved by changing the amount of azoles or by their protonation, alteration of the steric hindrance of the substituents in the heterocycles, and by changing the reaction temperature. Complexes 1–4 were characterized using elemental (C, H, N) analyses, 1H, 13C{1H} NMR, FTIR, HRESI-MS, TG-DTA, X-ray crystallography, and 5 was characterized using HRESI-MS and X-ray crystallography. Unconventional metallophilic contacts NiII⋯NiII were observed in dimer 3 in the solid state (the distance for Ni⋯Ni is 2.99 Å, whereas the double Bondi’s vdW radius for Ni is 3.26 Å) and the reality of these interactions was confirmed theoretically by the topological analysis of the electron density distribution (AIM method). The estimated energy for these non-covalent Ni⋯Ni interactions (ca. 4 kcal mol−1) fills the gap in the reported energies of the metal⋯metal interactions in a series comprising of NiII⋯NiII (this work), PdII⋯PdII (4.3–6.0 kcal mol−1), and PtII⋯PtII (3.9–11.7 kcal mol−1).

 

Inorganica Chimica Acta, 2017, 455, 607–612

Mikhail A. Kinzhalov, Galina L. Starova, Vadim P. Boyarskiy

“Interaction of benzene-1,2-diamines with isocyanide complexes of palladium(II): Insight into the mechanism”

Inorganica Chimica Acta, 2017, 455, 607–612
DOI:10.1016/j.ica.2016.05.014
источник: http://www.sciencedirect.com/science/article/pii/S0020169316302432

Reactivity of 4-toluidine (2) and 4,5-dimethylbenzene-1,2-diamine (3) were compared in coupling with the palladium-bis(isocyanide) complex cis-[PdCl2(CNXyl)2] (Xyl = 2,6-Me2C6H3, 1), mixed isocyanide/diaminocarbene species cis-[PdCl2(CNXyl){C(NHXyl)double bond; length as m-dashNH(4-C6H4CH3)}] (4), and cis-[PdCl(CNXyl){C(NHXyl)double bond; length as m-dashNHC6H2(Me)2NH2}]Cl (5). In these Pd(II)-mediated reactions, 4,5-dimethylbenzene-1,2-diamine (3) was significantly more reactive than 4-toluidine (2), leading to the first mixed bis(diaminocarbene) complex cis-[PdCl{C(NHR)double bond; length as m-dashNHC6H2X2NH2}{C(NHXyl)double bond; length as m-dashNH(4-C6H4CH3)}]Cl (6) containing two different diaminocarbene ligands. Complex 6 was isolated and characterized by elemental analyses (C, H, N), HRESI+-MS, IR, 1H and 13C{1H} NMR spectroscopies, and single-crystal X-ray diffraction.

 

Excursion

Students and lecturers from St. Petersburg State Technological Institute visited CMR. Mikhail Vovk has briefly demonstrated modern equipment of center and described its main application for users purposes.

Glass Phys Chem, 2017, 43, 70–74

V.V. Tomaev, A.S. Mazur, A.S. Grevtsev

“A study of the process of thermal oxidation of lead selenide by the NMR and XRD methods”

Glass Phys. Chem., 2017, 43, 70–74
DOI:10.1134/S1087659617010163

Studies of the process of oxidation of powder samples of lead selenide in a dry air atmosphere have been performed. As shown by the methods of X-ray diffraction and scanning electron microscopy, the process of thermal treatment of samples resulted in the formation of the PbSeO3 phase, aside from the initial PbSe phase. Studies by the method of nuclear magnetic response (NMR) allowed revealing the dynamics of changes in the spectrum under the changed thermal treatment conditions.

 

Eur. J. Mineral., 2016, 28, 931–941

T.L. Panikorovskii, S.V. Krivovichev, E.V. Galuskin, V.V. Shilovskikh, A.S. Mazur, A.V. Bazai

“Si-deficient, OH-substituted, boron-bearing vesuvianite from Sakha-Yakutia, Russia: a combined single-crystal, 1H MAS-NMR and IR spectroscopic study”

Eur. J. Mineral., 2016, 28, 931–941
DOI:10.1127/ejm/2016/0028-2570

source: http://www.ingentaconnect.com/content/schweiz/ejm/2016/00000028/00000005/art00006

Single crystals of Si-deficient vesuvianite with significant degree of hydrogarnet-type (SiO4)4−–(O4 H4)4− substitution occur as epitactic overgrowth on the surface of large wiluite crystals from the Wiluy River, Sakha–Yakutia, Russia. Electron-microprobe analysis revealed considerable Si-deficiency, Si ranging from 16.30 to 17.50 apfu. The crystal structure of the mineral has been refined in the P4/nnc space group, a = 15.5876(4), b = 11.8021(5) Å to R 1 = 0.028 for 1533 unique observed reflections. The refinement of the site-occupancy factors confirmed significant vacancy at the Z(1) and Z(2) sites (27% and 10%, respectively), with associated increase of the Z(1)–O and Z(2)–O bond lengths to 1.697 and 1.655 Å, respectively. The increased size of the Z(1) tetrahedra results in the compression of the X(1) polyhedra, while the expansion of the Z(2) tetrahedra is compensated by the compression of the X(4) polyhedra. As a result, the significant degree of the hydrogarnet-type substitutions does not have an essential influence upon the unit-cell parameters compared to the usual defect-free vesuvianite. Thermogravimetric (TGA) and differential scanning calorimetry (DSC) curves indicated two steps of the weight loss in the temperature ranges of 600–900°C (2.08 wt%) and 1014°C (2.22 wt%). The total weight loss is estimated as 4.30%, which is in good agreement with the total content of OH estimated as 13.72 apfu. The 1H solid state MAS-NMR demonstrates the presence of a strong additional line at 3.38 ppm compared to the usual vesuvianite, which is explained by the existence of the additional H(3) site. The infrared spectrum in the OH-stretching vibration region shows the additional (B′) absorption band at 3618 cm−1 typical for a hydrogarnet-type substitution.

 

ASI


Excursion for the guests from Agency for Strategic Initiatives  was carried out in CMR.

DPX 300


Trableshoting of cooling sistem of Bruker DPX 300.

Colloid Surface A, 2017, 518, 273-282

A.S. Koneva, E.A. Safonova, P.S. Kondrakhina, M.A. Vovk, A.A. Lezov, Yu.S. Chernyshev, N.A. Smirnova

“Effect of water content on structural and phase behavior ofwater-in-oil (n-decane) microemulsion system stabilized by mixednonionic surfactants SPAN 80/TWEEN 80”

Colloid Surface A, 2017, 518, 273-282
DOI:10.1016/j.colsurfa.2017.01.020
источник: http://www.sciencedirect.com/science/article/pii/S0927775717300201

For the search of effective microemulsion systems with the properties demanded for various applica-tions the knowledge of structural properties of the reverse microemulsions for various compositionsand temperatures is of high value. In the present study, the microstructure and diffusion of the compo-nents of water-in-n-decane Winsor IV microemulsions stabilized by a mixture of nonionic surfactantsSpan 80 (sorbitane monooleate, HLB 4.9) and Tween 80 (polyoxyethylene sorbitan monooleate, HLB15.0) at the weight ratios 49:51 (i.e. at the maximal ability to solubilize water) were investigatedby viscosimetry, PGSTE NMR and DLS. The system phase diagram obtained at 298.2 K includes theintermediate heterogeneous region between the reverse micelles region and the microemulsions. Thewater-to-surfactant molar ratio was changed up to 15.5 (13 wt.% of water) at the weight ratios n-decane:surfactants 65:35 and 85:15. The microemulsion droplets are spherical (that is corresponded also to thecryo-TEM data) and grow with the increase of water content. The temperature effect on the aggregatesdiffusion (and on the aggregates size) in the range 298.2–318.2 K is not pronounced. The bimodal distri-butions of the diffusion coefficients determined using both DLS and PGSTE NMR methods are specific for the system. The slower diffusion mode relates to the diffusion of mixed microemulsion droplets with theradii Rh ∼10–20 nm. The second stable form of nanoaggregates are “dry” micelles with Rh ∼ 1–2 nm. Thedata on the diffusion coefficients are of special interest in particular for the molecular dynamic simulationof the reverse micelles or of the microemulsion droplets.

 

CMR projects in 2016


In total, 99 new projects have been submitted to CMR in 2016. More than 21 000 individual measurement requests have been fulfilled. We hope that in 2017 our contribution to the research and education will be even stronger! Good luck with your work!

December

Total in December 1938 service applications were carried out.
All together measured:

  • 1852 1H spectra
  • 310 13C spectra
  • 155 DEPT spectra
  • 22 COSY spectra
  • 15 NOESY spectra
  • 36 31P spectra
  • 28 19F spectra

212 applications were carried out.