Abstract: The present application discloses compositions for thin film dye-sensitized solar cells in which nanoparticles of semiconductor material are tethered together in a nanonodular network using a multi-functional linking compound.

Abstract: Disclosed is a method of producing a hafnium amide complex represented by general formula: Hf(NR4R5)4, characterized by comprising: carrying out a reduced-pressure distillation after a lithium alkylamide represented by general formula: Li(NR4R5) is added to and allowed to react with a tertiary hafnium alkoxide complex represented by general formula: Hf[O(CR1R2R3)]4. (In the formulas, R1, R2 and R3 independently represent either a phenyl group, a benzyl group, or a primary, secondary or tertiary alkyl group having a carbon number 1-6; and R4 and R5 independently represent either a methyl group or an ethyl group; however, a case where all of R1, R2 and R3 are methyl groups, and a case where one of R1, R2 and R3 is an ethyl group and the other two are methyl groups are excluded.

Abstract: Microstructured films comprising surface modified inorganic oxide particles, surface modified inorganic nanoparticles having a high refractive index, and polymerizable resins are described.

Abstract: The present techniques relates generally to polyolefin catalysts and, more specifically, to preparing a precursor compound for an unsymmetric metallocene catalyst, for using the precursor compound to prepare catalysts, and for employing the precursor compounds to prepare catalysts for polyolefin polymerizations.

Abstract: The present invention relates to substances which can be applied to the technical fields of gas storages, polymerization catalysts and optical isomers, their intermediates, and processes for preparing the same, which is characterized in that 1) possible disintegration of structure of the scaffold material (SM) is impeded, and 2) they are prepared by a simple manufacturing system as compared to the substances conventionally suggested in the application field. Specifically, it relates to scaffold material-transition metal hydride complexes comprised of scaffold material (SM) and transition metal hydride (M1H(n-1)) which is chemically bonded to the functional groups formed on the scaffold material, SM-transition metal halide complex and SM-transition metal ligand complex as the precursors, and a process for preparing the same. The SM-transition metal hydride complex according to the present invention is a substance for hydrogen storage which adsorbs hydrogen via Kubas adsorption.

Abstract: Transition metal complexes of selected monoanionic phosphine ligands, which also contain a selected Group 15 or 16 (IUPAC) element and which are coordinated to a Group 3 to 11 (IUPAC) transition metal or a lanthanide metal, are polymerization catalysts for the (co)polymerization of olefins such as ethylene and ?-olefins, and the copolymerization of such olefins with polar group-containing olefins. These and other nickel complexes of neutral and monoanionic bidentate ligands copolymerize ethylene and polar comonomers, especially acrylates, at relatively high ethylene pressures and surprisingly high temperatures, and give good incorporation of the polar comonomers and good polymer productivity. These copolymers are often unique structures, which are described.

Abstract: The invention relates to a composite material comprising nanoparticles of at least one metal derivative and at least one type of carboxylic and/or sulfonic acid derivative organic compound chemically bound in a covalent manner with said nanoparticles by means of at least one carboxylic and/or sulfonic function.

Abstract: This invention relates to organometallic compounds represented by the formula (L1)xM(L2)y wherein M is a metal or metalloid, L1 and L2 are different and are each a hydrocarbon group or a heteroatom-containing group; x is a value of at least 1; y is a value of at least 1; x+y is equal to the oxidation state of M; and wherein (i) L1 has a steric bulk sufficiently large such that, due to steric hinderance, x cannot be a value equal to the oxidation state of M, (ii) L2 has a steric bulk sufficiently small such that, due to lack of steric hinderance, y can be a value equal to the oxidation state of M only in the event that x is not a value of at least 1, and (iii) L1 and L2 have a steric bulk sufficient to maintain a heteroleptic structure in which x+y is equal to the oxidation state of M; a process for producing the organometallic compounds, and a method for producing a film or coating from organometallic precursor compounds.

Abstract: This invention relates to Group 4 catalyst compounds containing di-anionic tridentate nitrogen/oxygen based ligands. The catalyst compounds are useful, with or without activators, to polymerize olefins, particularly a-olefins, or other unsaturated monomers. Systems and processes to oligomerize and/or polymerize one or more unsaturated monomers using the catalyst compound, as well as the oligomers and/or polymers produced therefrom are also provided.

Abstract: Group 4 catalyst compounds containing di-anionic tridentate nitrogen/oxygen based ligands are provided. The catalyst compounds are useful, with or without activators, to polymerize olefins, particularly ?-olefins, or other unsaturated monomers. Systems and processes to oligomerize and/or polymerize one or more unsaturated monomers using the catalyst compound, as well as the oligomers and/or polymers produced therefrom are also provided.

Abstract: The present invention discloses active oligomerization or polymerization catalyst systems based on imino-quinolinol complexes.

Abstract: Catalyst compositions comprising a first metallocene compound, a second metallocene compound, an activator-support, and an organoaluminum compound are provided. An improved method for preparing cyclopentadienyl complexes used to produce polyolefins is also provided.

Abstract: Disclosed is a novel transition metal compound which is used for forming a metallocene catalyst for olefin polymerization. Specifically disclosed is a novel transition metal compound represented by the general formula below which enables to form a metallocene catalyst that has a balanced reactivity with ethylene and a comonomer selected from ?-olefins having 3-20 carbon atoms and enables to produce an ?-olefin polymer having a high molecular weight. Also specifically disclosed are a catalyst for olefin polymerization containing such a transition metal compound, and a method for producing a propylene/ethylene-?-olefin block copolymer wherein such a catalyst is used.

Abstract: The invention relates to a process for the synthesis of spheroidal magnesium alkoxide having improved mechanical strength and narrow particle size distribution, the process comprising reacting magnesium metal, in the presence of iodine, with a mixture of alcohols by step-wise heating first in the range of 40° C. to 65° C. for a period of 2 hours and then in the range of 65° C. to 80° C. for a period of 1 hour, further by maintaining reaction temperature at 80° C. for a period of 6-10 hours, the vapours of the mixture produced during the reaction being condensed in an overhead condenser, hydrogen gas produced during the reaction being vented off and the mixture of alcohols left after the reaction being filtered and reused. The invention also relates to spheroidal magnesium alkoxide particles synthesized by the method, to the Ziegler natta procatalyst synthesized by using the alkoxide and to the polymer resin synthesised using the procatalyst.

Abstract: An oxygen-bridged bimetallic complex of the general formula (I) Cp2R1M1-O-M2R22Cp??(I), wherein Cp is independently a cyclopentadienyl, indenyl or fluorenyl ligand which can be substituted, or a ligand isolobal to cyclopentadienyl, R1, R2 independently are halide, linear or branched or cyclic alkyl, aryl, amido, phosphido, alkoxy or aryloxy groups, which can be substituted, M1 is Zr, Ti or Hf, and M2 is Ti, Zn, Zr or a rare earth metal. The complex can be useful as a polymerization catalyst.

Abstract: There is provided a hybrid and/or complex material or the like which can realize a high-efficient photoelectric conversion material or the like. One aspect of the present invention lies in a dye-sensitized solar cell device 10, characterized by including: a first substrate 11; a first conductive layer 12 formed on the first substrate; a Pt catalyst layer formed on the first conductive layer; an electrolyte layer 13 formed on the Pt catalyst layer; a dye-adsorbed metal oxide layer 14 formed on the electrolyte layer in which 7,7,8,8-tetracyanoquinodimethane is adsorbed to an anatase type titanium oxide; a second conductive layer 15 formed on the dye-adsorbed metal oxide layer; and a second substrate 16 formed on the second conductive layer. According to this composition above, there is obtained a high-efficient dye-sensitized solar cell device in which light can be converted efficiently over wide wavelengths.

Abstract: Processes are provided for producing transition metal amidos and/or imidos. In methods according to this invention, at least one halogenated transition metal, an amine compound and a solvent are combined, followed by the addition of an alkylated metal or a Grignard reagent to produce the transition metal amide and/or imido.

Abstract: Catalysts useful for polymerizing olefins are disclosed. The catalysts comprise an activator and a Group 4 metal complex that incorporates a dianionic, tridentate 2-aryl-8-anilinoquinoline ligand. In one aspect, supported catalysts are prepared by first combining a boron compound having Lewis acidity with excess alumoxane to produce an activator mixture, followed by combining the activator mixture with a support and the tridentate, dianionic Group 4 metal complex. The catalysts are easy to synthesize, support, and activate, and they enable facile production of high-molecular-weight polyolefins.

Abstract: The invention relates to a process for synthesizing tertiary phosphines by reacting halophosphines with organomagnesium compounds in the presence of copper compounds and optionally of salts.

Abstract: Disclosed are a transition metal complex having a high catalytic activity for the preparation of an ethylene homopolymer or a copolymer of ethylene and ?-olefin and a catalyst composition comprising the same. More specifically, there are provided a transition metal complex having, around a group IV transition metal, a cyclopentadiene derivative and at least one aryl oxide ligand with a heterocyclic aryl derivative substituted at the ortho-position thereof, with no crosslinkage between the ligands, a catalyst composition comprising the transition metal complex and an organoaluminum compound or boron compound as cocatalyst, and a method for the preparation of high molecular weight ethylene homopolymers or copolymers of ethylene and ?-olefin using the same.

Abstract: The present invention discloses the use of aromatic diamine ligands to prepare catalyst systems suitable for the oligomerization or polymerization of ethylene and alpha-olefins.

Abstract: The present disclosure discloses a catalyst for directly producing a lactide which is a cyclic ester used as a monomer for polylactides, and a method for directly producing a lactide using the catalyst, the method including the transesterification reaction between two molecules of an ester of lactic acid or a mixture containing the ester of lactic acid with a small amount of lactic acid and oligomer of lactic acid under an inert environment in the presence of a titanium-based catalyst or a catalyst mixture containing the titanium-based catalyst so as to produce lactide while simultaneously removing an alcohol (ROH) generated as a by-product.

Abstract: The present invention relates to a transition metal complex useful as a transition metal catalyst in the preparation of an ethylene homopolymer or a copolymer of ethylene and an ?-olefin, a catalyst composition comprising the same and a process of preparing an ethylene homopolymer or a copolymer of ethylene and an ?-olefin using the same. More particularly, it relates to a transition metal complex having a cyclopentadiene derivative and at least one phenyl oxide ligand substituted at the 2-position of phenyl with, for example, a silyl group having a C1-C30 hydrocarbon group or a C1-C20 hydrocarbon group, around a group IV transition metal, with no crosslinkage between the ligands, a catalyst composition comprising the transition metal complex and a cocatalyst selected from the group consisting of an aluminoxane and a boron compound, and a process for preparing an ethylene homopolymer or a copolymer of ethylene and an ?-olefin using the same.

Abstract: Disclosed is a functionalized nanoparticle of a metal oxide. The nanoparticle has at its surface at least one organic moiety. The moiety is covalently bonded to the surface of the nanoparticle via at least one Si—O bond. The moiety has a functional group suitable for nucleophilic substitution. The nucleophilic substitution reaction can be used to attach any desired organic compound to the surface of the nanoparticle.

Abstract: Zirconium precursors of the formulae Such precursors are liquids at room temperature, and can be employed in vapor deposition processes such as ALD to form zirconium-containing films, e.g., high k dielectric films on microelectronic device substrates. The zirconium precursors can be stabilized in such vapor deposition processes by thermal stabilization amine additives.

Abstract: A compound which has thermal stability and moderate vaporizability and is satisfactory as a material for the CVD or ALD method; a process for producing the compound; a thin film formed from the compound as a raw material; and a method of forming the thin film. A compound represented by the general formula (1) is produced by reacting a compound represented by the general formula (2) with a compound represented by the general formula (3). The compound produced is used as a raw material to form a metal-containing thin film. [Chemical formula 1] (1) [Chemical formula 2] (2) [Chemical formula 3] Mp(NR4R5)q(3) (In the formulae, M represents a Group 4 element, aluminum, gallium, etc.; n is 2 or 3 according to cases; R1 and R3 each represents C1-6 alkyl, etc.; R2 represents C1-6 alkyl, etc.; R4 and R5 each represents C1-4 alkyl, etc.; X represents hydrogen, lithium, or sodium; p is 1 or 2 according to cases; and q is 4 or 6 according to cases).

Abstract: There is provided a method for immobilizing a bio-material on a surface of titanium dioxide nanoparticles (TiO2) as a highly reflective material to enhance sensitivity of a resonant reflection biosensor. The method for immobilizing a bio-material may be useful to easily immobilize bio-materials such as proteins, DNA, RNA and enzymes on surfaces of titanium dioxide (TiO2) nanoparticles using the chemical reaction, and significantly improve sensitivity of a resonant reflection biosensor by determining the antigen-antibody reaction in the resonant reflection biosensor using the immobilized secondary antien.

Abstract: The present invention relates to titanium catalysts for asymmetric synthesis reactions produced by bringing a reaction mixture obtained by contacting water and a titanium alkoxide into contact with an optically active ligand represented by the general formula (a), wherein R1, R2, R3, and R4 are independently a hydrogen atom, an alkyl group, or the like, and A* represents a group with two or more carbon atoms having an asymmetric carbon atom or axial asymmetry. The invention further relates to a process for asymmetric cyanation of imines, wherein the process comprises reacting an imine with a cyanating agent in the presence of the titanium catalyst.

Abstract: Disclosed are certain complexes of AFC compounds and binding agents. Such complexes are useful, among other things, in the treatment of inflammatory diseases or disorders.

Abstract: A novel metal compound of general formula (1), a material for chemical vapor phase growth containing the compound, and a process for forming a metal-containing thin film by chemical vapor phase growth using the material. Among the compounds of formula (1), those wherein X is a chlorine atom are preferred because of inexpensiveness and high volatility. When M is titanium, those wherein m is 1 are preferred as having a greater difference between a volatilization temperature (vapor temperature) and a deposition temperature (reaction temperature), which provides a broader process margin. In formula (1), M is titanium, zirconium, or hafnium; X is a halogen atom; and m is 1 or 2.

Abstract: The present invention includes polyol modified titanium compounds, their preparation and use in methods to make biomolecule compatible monolithic titania. The invention also includes the use of the biomolecule compatible monolithic titania in bioanalytic applications, for example in biosensors, chromatographic columns, microarrays and bioaffinity columns.

Abstract: The present invention relates to an advanced preparation method of organic-transition metal hydride used as hydrogen storage materials, the method including: preparing organic-transition metal-aluminum hydride complexes by reacting the organic-transition metal halide with metal aluminum hydride compounds; and preparing the organic-transition metal hydride by reacting the organic-transition metal aluminum hydride complexes with Lewis bases. Since the preparation method of the organic-transition metal hydride according to the present invention does not use catalysts, it has advantages that it does not cause problems due to poisoning and can prepare the organic-transition metal hydride at high yield under less stringent conditions. The hydrogen storage materials containing the organic-transition metal hydride prepared from the preparation method can safely and reversibly store a large amount of hydrogen.

Abstract: A nanostructure and method for assembly thereof are disclosed. An exemplary nanostructure includes a photocatalytic nanoparticle; a first tier of metal nanoparticles, each metal nanoparticle of the first tier being linked about the photocatalytic nanoparticle; and a second tier of metal nanoparticles, each metal nanoparticle of the second tier being linked to one of the metal nanoparticles of the first tier and located a distance from the photocatalytic nanoparticle greater than a distance between a metal nanoparticle of the first tier and the photocatalytic nanoparticle.

Abstract: A metal precursor, selected from among: (i) precursors of the formula (NR1R2)4-xM(chelate)x, and (ii) precursors of the formula (NR10R11)4-2yM(12RN(CH2)zNR13)y, wherein: x=1, 2, 3, or 4; M=Ti, Zr, or Hf; each chelate is independently selected from among guanidinate, amidinate, and isoureate ligands of specific formula; y is 0, 1, or 2; and each of R1, R2, R10, R11, R12 and R13 is independently selected from among H, C1-C12 alkyl, C1-C12 alkylamino, C1-C12 alkoxy, C3-C10 cycloalkyl, C2-C12 alkenyl, C7-C12 aralkyl, C7-C12 alkylaryl, C6-C12 aryl, C5-C12 heteroaryl, C1-C10 perfluoroalkyl, and silicon-containing groups selected from the group consisting of silyl, alkylsilyl, perfluoroalkylsilyl, triarylsilyl and alkylsilylsilyl, aminoalkyl, alkoxyalkyl, aryloxyalkyl, imidoalkyl, acetylalkyl, and N-bonded functionality between two different nitrogen atoms of the precursor can be C1-C4 alkylene, silylene (—SiH2—), or C1-C4 dialkylsilylene.

Abstract: Processes are provided for producing transition metal amides. In methods according to this invention, at least a halogenated transition metal and an amine are combined in a solvent to produce an intermediate composition and an alkylated metal or a Grignard reagent is added to the intermediate composition to produce the transition metal amide.

Abstract: The present invention relates to titanium catalysts for asymmetric synthesis reactions produced by bringing a reaction mixture obtained by contacting water and a titanium alkoxide into contact with an optically active ligand represented by the general formula (a), wherein R1, R2, R3, and R4 are independently a hydrogen atom, an alkyl group, or the like, and A* represents a group with two or more carbon atoms having an asymmetric carbon atom or axial asymmetry. The invention further relates to a process for asymmetric cyanation of imines, wherein the process comprises reacting an imine with a cyanating agent in the presence of the titanium catalyst.

Abstract: Crystals of [VOBDC](H2BDC)0.71 were synthesized hydrothemally. The guest acid molecules were removed by heating in air to give high quality single crystals of VOBDC. VOBDC was observed to show crystal-to-crystal transformations on absorption of the guest molecules aniline, thiophene and acetone from the liquid phase. Accurate structural data of the guest molecules and framework deformations were obtained from single crystal X-ray data. VOBDC was also shown to absorb selectively thiophene and dimethyl sulphide from methane.

Abstract: Metal films are deposited with uniform thickness and excellent step coverage. Copper metal films were deposited on heated substrates by the reaction of alternating doses of copper(I) NN?-diispropylacetamidinate vapor and hydrogen gas. Cobalt metal films were deposited on heated substrates be the reaction of alternating doses of cobalt(II) bis(N,N?-diispropylacetamidinate) vapor and hydrogen gas. Nitrides and oxides of these metals can be formed by replacing the hydrogen with ammonia or water vapor, respectively. The films have very uniform thickness and excellent step coverage in narrow holes. Suitable applications include electrical interconnects in microelectronics and magnetoresistant layers in magnetic information storage devices.

Abstract: The invention relates to a composite material comprising nanoparticles of at least one metal derivative and at least one type of carboxylic and/or sulfonic acid derivative organic compound chemically bound in a covalent manner with said nanoparticles by means of at least one carboxylic and/or sulfonic function.

Abstract: Novel trans-1,2-diphenylethylene derivatives are synthesized which can be used to form nanoparticles-monomer-nanomolecule-receptor nanosensors. These trans-1,2-diphenyl-ethylene derivatives are soluble in both water and organic solvents, highly fluorescent and can be synthesized in high yields. The trans-1,2-diphenylethylene derivatives are bonded to a nanoparticle, a nanomolecule bonded to the derivative and a receptor bonded to the nanomolecule to form a nanosensor that can be used to detect chemical and biological agents.

Abstract: Ligands, compositions, and metal-ligand complexes that incorporate phenol-heterocyclic compounds are disclosed that are useful in the catalysis of transformations such as the polymerization of monomers into polymers. The catalysts have high performance characteristics, including high comonomer incorporation into ethylene/olefin copolymers, where such olefins are for example, 1-octene, propylene or styrene. The catalysts particularly polymerize styrene to form polystyrene.

Abstract: Metal films are deposited with uniform thickness and excellent step coverage. Copper metal films were deposited on heated substrates by the reaction of alternating doses of copper(I) NN?-diispropylacetamidinate vapor and hydrogen gas. Cobalt metal films were deposited on heated substrates b the reaction of alternating doses of cobalt(II) bis(N,N?-diispropylacetamidinate) vapor and hydrogen gas. Nitrides and oxides of these metals can be formed by replacing the hydrogen with ammonia or water vapor, respectively. The films have very uniform thickness and excellent step coverage in narrow holes. Suitable applications include electrical interconnects in microelectronics and magnetoresistant layers in magnetic information storage devices.

Abstract: Intermediates and methods for forming activated metal complexes bound to surfaces on oxide layers, immobilizing beads to the modified surface and articles produced thereby are described. Hydroxyl groups on the oxide surfaces are reacted with a metal reagent complex of the formula Y(L-Pol)m, where Y is a transition metal, magnesium or aluminum, L is oxygen, sulfur, selenium or an amine, and “Pol” represents a passivating agent such as a methoxyethanol, a polyethylene glycol, a hydrocarbon, or a fluorocarbon. The resulting modified surface can be further reacted with a passivating agent having a phosphate functional group or a plurality of functional groups that are reactive with or that form complexes with Y.

Abstract: In a method of forming a layer, a precursor including a metal and a ligand coordinating to the metal is stabilized by contacting the precursor with an electron donating compound to provide a stabilized precursor into a substrate. A reactant is introduced into the substrate to bind to the metal in the stabilized precursor. The precursor stabilized by the electron donating compound has an improved thermal stability and thus the precursor is not dissociated at a high temperature atmosphere, and the layer having a uniform thickness is formed on the substrate.

Abstract: The present invention relates to a more advanced preparation method of organic-transition metal hydride as a hydrogen storage material, precisely a more advanced preparation method of organic-transition metal hydride containing aryl or alkyl group that facilitates safe and reverse storage of massive amount of hydrogen. The present invention relates to a preparation method of an organic-transition metal hydride comprising the steps of preparing a complex reducing agent composition by reacting alkali metal, alkali earth metal or a mixture thereof and (C10˜C20) aromatic compound in aprotic polar solvent; and preparing organic-transition metal hydride by reacting the prepared complex reducing agent composition and organic-transition metal halide. The method of the present invention has advantages of minimizing the numbers and the amounts of byproducts by using a complex reducing agent and producing organic-transition metal hydride safely without denaturation under more moderate reaction conditions.

Abstract: An ore containing crystal water (bond water) is heated to dehydrate the crystal water in the form of water vapor, thereby rendering the ore porous to generate a porous ore. Next, the porous ore is forced into contact with a dry-distilled gas (organic gas) obtained by dry-distillation of an organic substance such as wood and the like or an organic liquid such as tar and the like. An organic compound such as tar and the like contained in the dry-distilled gas or organic liquid adheres to the surface of the porous ore. Next, the porous ore adhered with an organic compound is heated at 500° C. or higher, to generate an ore in which a part of an oxide of an element such as iron and the like contained is reduced by carbon in the organic compound.

Abstract: Improved methods for performing atomic layer deposition (ALD) are described. These improved methods provide more complete saturation of the surface reactive sites and provides more complete monolayer surface coverage at each half-cycle of the ALD process. In one embodiment, operating parameters are fixed for a given solvent based precursor. In another embodiment, one operating parameter, e.g. chamber pressure is altered during the precursor deposition to assure full surface saturation.

Abstract: New ligands and compositions with bridged bis-aromatic ligands are disclosed that catalyze the polymerization of monomers into polymers. These catalysts with metal centers have high performance characteristics, including higher comonomer incorporation into ethylene/olefin copolymers, where such olefins are for example, 1-octene, propylene or styrene. The catalysts also polymerize propylene into isotactic polypropylene.

Abstract: The present invention relates to an organic-transition metal complex which can safely and reversibly store hydrogen in a high capacity, and a process for preparing the same. In order to achieve the objects, the hydrogen storage material according to the invention comprises a complex generated by combination of an organic substance containing a hydroxyl (—OH) group(s) with a transition metal containing compound, which can more effectively store hydrogen with more than one transition metal being bonded per molecule. Examples of the organic substances containing hydroxyl (—OH) group(s) include alkyl derivatives such as ethylene glycol, trimethylene glycol and glycerol, and hydroxyl-containing aryl derivatives such as fluoroglucinol. As the transition metal, titanium (Ti), vanadium (V) and scandium (Sc), which can make Kubas binding, may be mentioned.

Abstract: The invention provides a process for producing a metallocene compound of formula (3) wherein R1 to R9 independently denote a hydrogen atom, a halogen atom, an alkyl, or the like; R10 denotes a halogen atom, an alkyl, an alkoxy, or the like; X5 and X6 independently denote a hydrogen atom, a halogen atom, or the like; and M denotes a transition metal atom of Group 4 of the Periodic Table, which process is characterized by reacting a silicon-substituted cyclopentadiene compound of formula (1) wherein R1 to R10 independently denote the same as described above; R11 denotes a hydrocarbon group or a tri-substituted silyl; and R12 to R14 independently denote a halogen atom or a hydrocarbon group, with a transition metal compound of the following formula (2) wherein M denotes the same as described above; X1, X2, X3, and X4 independently denotes a hydrogen atom, a halogen atom, an alkyl, or the like, in a solvent containing an aromatic hydrocarbon.