Theoretical free energies of electron transfer, electrochemical properties, electron transfer kinetic and quantitative structural relationships studies of alkynyldihydrofullerene in [X-UT-Y][R-C60–M+] supramolecular complexes

The isolated pentagon rule (IPR) states that all pentagonal carbon rings are isolated in the most stable fullerenes. Fullerenes (buckministerfullerene) are a class of spherical carbon allotrope group with unique properties. Electron transfer between fullerene C60 derivatives such as alkynyldihydrofullerene (1-alkynyl-C60 carbanion) and other molecules are thought to involve the transfer of electrons between molecules surrounding the fullerene cage. One class of electron-transfer molecules has introduced as [X-UT-Y][R-C60–M+](R=tert-Bu- & H–C≡C-; M=Li & K). The supramolecular complexes [X-UT-Y] (1-9) and [R-C60–M+] (R=tert-Bu- & H–C≡C-; M=Li & K) are shown to possess a previously unreported host-guest interaction for electron transfer processes. The unsaturated, thiocrown ethers (1-9, with cis-geometry) (described as [X-UT-Y], where X and Y indicate the numbers of carbon and sulfur atoms, respectively) are a group of crown ethers that display interesting physiochemical properties in light of their conformational restriction compared to a corresponding saturated system, as well as the sizes of their cavities. Topological indices have been successfully used to construct mathematical methods that relate the structural data to the various chemical and physical properties. To establish a good relationship between the structures of 1-9 with derivatives of alkynyldihydrofullerene (1-alkynyl-C60 carbanion) as [R-C60–M+] (R=tert-Bu- & H–C≡C-; M=Li & K) in DMSO and THF solvents 12-38, an index (mcs) is utilized. This index is the ratio of the sum of the number of carbon atoms (nc) and the number of sulfur atoms (ns) with the product of these two numbers for 1-9. In this study, were investigated the relationships between this index and the first to third free energies of electron transfer (ΔGet(n); n=1-3, which is given by the Rehm-Weller equation) between 1-9 and [R-C60–M+] (R=tert-Bu- & H–C≡C-; M=Li & K) as [X-UT-Y][R-C60–M+](R=tert-Bu- & H–C≡C-; M=Li & K) supramolecular complexes in DMSO and THF solvents. The first to third free energies of electron transfer and the kinetic rate constants of the electron transfers, ΔG#et(n) and ket (n=1-3), respectively, were also calculated for [X-UT-Y][R-C60–M+] (R=tert-Bu- & H–C≡C-; M=Li & K) in DMSO and THF, in accordance with the Marcus theory

Chemical composition analysis of the essential oil of Solanumn nigrum L. by HS/SPME method and calculation of the biochemical coefficients of the components

AbstractThe volatile constituents of the essential oil of wild Solanumn nigrum L. obtained from the Kurdistan of Iraq were extracted by head-space/solid-phase micro-extraction (HS/SPME) and were analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). Of a total of twenty compounds in the oil, all of them were identified. The main components were as follows: Dillapiole (22.22%), α-Cadinol (16.47%), para-Cymene (10.01%), (E)-1-(2,6,6-Trimethyl-1,3-cyclohexadien-1-yl)-2-buten-1-one or β-damascenone (9.08%), α-Phellandrene (8.48%), β-Pinene (5.93%), α-Bisabolol acetate (4.53%), (Z,E)-4,6,8-Megastigmatriene (4.09%), Phytol (2.49%), Linalyl butanoate (2.13%), 8-methylene-tricyclo[3.2.1.0(2,4)]octane (2.60%) and Limonene (2.03%). Some physicochemical properties, such as the logarithm of calculated octanol–water partitioning coefficients (logKow) and total biodegradation (TBd in mol/h) were calculated for compounds 1–20 from S. nigrum L

Study of the number of rings in carbon nano structures (fullerenes and nanotubes)

One of the questions is determining the number of rings in fullerenes and nanotubes. Here, for solving this problem, a simple, fast and high accuracy method is explained. Application of this method has shown good results. Determining the number of rings (NR) in carbon nanostructures such as fullerenes, nanotubes (SWNT) and other nanocarbon structures is the main aim of this study. This structural index that is based on the degrees of unsaturation may useful in the QSAR and QSPR studies concern to the carbon nanostructures

Theoretical studies of the free energies of electron transfer and electron transfer kinetics in nanostructure supramolecular complexes of cis-unsaturated thiocrown ethers and Ce and Gd endohedral metallofullerenes [X–UT–Y][M@C82] (M = Ce, Gd)

Unsaturated thiocrown ethers (described as [X–UT–Y], where X and Y indicate the numbers of carbon and sulfur atoms, respectively) with cis-geometry are a group of crown ethers that, in light of the size of their cavities and their conformational restriction compared to a corresponding saturated system (1–9), demonstrate interesting properties for physicochemical studies. Formation of endohedral metallofullerenes is thought to involve the transfer of electrons from the encapsulated metal atom(s) to the surrounding fullerene cage. Two of these molecules are the Ce@C82 (10) and Gd@C82 (11). The supramolecular complexes of 1–9 with Ce@C82 (10) and Gd@C82 (11) have been shown to possess a host–guest interaction for electron transfer processes, and these behaviors have previously been reported. The relationship between an index (which was introduced as the ratio of summation of the number of carbon atoms (nc) and the number of sulfur atoms (ns)) and oxidation potential (oxE1) of 1–9, as well as the free energies of electron transfer (ΔGet, by the Rehm–Weller equation) between 1–9 and 10 and 11 as [X–UT–Y][Ce@C82] (12) and [X–UT–Y][Gd@C82] (13) complexes, were investigated before. In this study, the first and second activation free energies of electron transfer and kinetic rate constants of the electron transfers, ΔGet(n)# and ket (n = 1,2), respectively, which are given by the previous studies for [X–UT–Y][Ce@C82] (12) and [X–UT–Y][Gd@C82] (13) complexes, were calculated in accordance with the Marcus theory

Quantitative structural relationship study of electrochemical properties on the nano structures of cis-unsaturated thiocrown ethers and their supramolecular complexes [X-UT-Y] [Sc-2@C-84] and [X-UT-Y] [Er-2@C-82]

Since the discovery of the fullerenes class of carbon compounds, the unusual structures and properties of these molecules and the many potential applications have been offered. Unsaturated thiocrown ethers with cis-geometry are a group of crown ethers that, in light of their conformational restriction compared to a corresponding saturated system and the size their cavities, (1-9) demonstrate interesting properties for physicochemical studies. Endohedral metalofullerenes M@CX were introduced as a new class of spherical fullerenes group with unique properties. Formation of endohedral metallofullerenes is thought to involve the transfer of electrons from the encapsulated metal atom(s) to the surrounding fullerene cage. Two of these molecules are the Sc2@C84 (10) and Er2@C82 (11). The supramolecular complexes of 1-9 with Sc2@C84 (10) and Er2@C82 (11) have been shown to possess a host-guest interaction for electron transfer processes, and these behaviors have previously been reported. Topological indices have been successfully used to construct effective and useful mathematical methods for finding good relationships between structural data and the various chemical and physical properties. To establish a good structural relationship between the structures of 1-9 with M@Cx that they were introduced here was utilized an index that is introduced by "cs". This index is the ratio of summation of the number of carbon atoms (nc) and the number of sulfur atoms (ns) with the product of these two scales for 1-9. In this study, the relationship between this index and oxidation potential (oxE1) of 1-9, as well as the free energy of electron transfer (Get, by the Rehm-Weller equation) between 1-9 and 10 and 11 as [X-UT-Y] [Sc2@C84] (12) and [X-UT-Y] [Er2@C82] (13) complexes are presented