The title complex, [Hf(C29H41N2)Cl3], was synthesized from HfCl4 and HC[C(Me)N( (i) Pr2C6H3)]2Li(Et2O) in toluene. The structure is isotypic with those of Ti(IV) and Zr(IV) complexes reported previously [Nikiforov et al. (2007 ▶). Dalton Trans. pp. 4149-4159; Kakaliou et al. (1999 ▶). Inorg. Chem. 38, 5964-5977]. There is a crystallographic mirror plane containing the Hf atom, one chloride liga...

Calix[8]arenes of conformational rigid were isolated. The NMR parameters of the structure of calix[8]arenes have been compared. The study of organic structures to form nanoporous materials is well-known in chemistry phenomena to find the crystal form of calix[8]arene as supramolecule. Investigated and compared hydrogen bonding, oxygen and nitrogen atoms effect on calix[8]arene and its complexes...

Calix[8]arenes of conformational rigid were isolated. The NMR parameters of the structure of calix[8]arenes have been compared. The study of organic structures to form nanoporous materials is well-known in chemistry phenomena to find the crystal form of calix[8]arene as supramolecule. Investigated and compared hydrogen bonding, oxygen and nitrogen atoms effect on calix[8]arene and its complexes...

To many, high-frequency (HF) radio communications is obsolete in this age of longdistance satellite communications and undersea optical fiber. Yet despite this, the HF band is used by defense agencies for backup communications and spectrum surveillance, and is monitored by spectrum management organizations to enforce licensing. Such activity usually requires systems capable of locating distant ...

compound (n,n-bis (salicylidene) 1,2-diaminophenylene) was prepared by condensation of ethanolsolution of 2-hydroxybanzaldehyde and 1,2-diaminophenylene. the compound was characterized by1h nmr, infrared spectroscopy (ft-ir) data and analytical data. the geometrical parameters andenergies have been obtained from density functional theory (dft) b3lyp method and hartree-fock (hf) method with 3-21...

Compound (N,N-bis (salicylidene) 1,2-diaminophenylene) was prepared by condensation of ethanolsolution of 2-Hydroxybanzaldehyde and 1,2-diaminophenylene. The compound was characterized by1H NMR, infrared spectroscopy (FT-IR) data and analytical data. The geometrical parameters andenergies have been obtained from Density Functional Theory (DFT) B3LYP method and Hartree-Fock (HF) method with 3-21...

using the gaussian 2003 software and mp2/ 6–311 ++ g** method for he: he, ne:ne andmp2/6-31g method for ar: ar, kr: kr and hf/sto-3g method for xe: xe, the optimizedinteraction energies between two like atoms of rare gases (he, ne, ar, kr and xe) as a functionof the distances between the centers of two considered atoms were evaluated and the resultswere interpreted according to the lennard – jo...

Let $G$ be a molecular graph with vertex set $V(G)$, $d_G(u, v)$ the topological distance between vertices $u$ and $v$ in $G$. The Hosoya polynomial $H(G, x)$ of $G$ is a polynomial $sumlimits_{{u, v}subseteq V(G)}x^{d_G(u, v)}$ in variable $x$. In this paper, we obtain an explicit analytical expression for the expected value of the Hosoya polynomial of a random benzenoid chain with $n$ hexagon...