1271-54-1

Usage

Uses

Used in Olefin Hydrogenation:
DIBENZENECHROMIUM is used as a catalyst for olefin hydrogenation, a process that involves the conversion of unsaturated hydrocarbons (olefins) into saturated hydrocarbons (alkanes) by adding hydrogen. This application is crucial in the petrochemical industry for producing various chemicals and fuels.
Used in Electron Transfer Chain Catalysis Mechanism:
DIBENZENECHROMIUM serves as a catalyst in the electron transfer chain catalysis mechanism, which is essential in various biochemical processes, including cellular respiration and photosynthesis. Its role in facilitating electron transfer makes it a vital component in the energy production of living organisms.
Used in Hydrosilation of Ketones and Aldehydes:
In the chemical industry, DIBENZENECHROMIUM acts as a pre-catalyst for the hydrosilation of ketones and aldehydes. This process involves the addition of a silicon-hydrogen bond to a carbonyl group, leading to the formation of a silyl ether and a hydrogen molecule. This application is significant in the synthesis of various organic compounds and materials.
Used in Dehydrocoupling of Triphenylsilane with Primary Alcohols:
DIBENZENECHROMIUM is also utilized as a pre-catalyst in the dehydrocoupling of triphenylsilane with primary alcohols. This reaction results in the formation of a silyl ether and a phenyl group, which are valuable intermediates in organic synthesis and the production of various chemicals and materials.

Safety Profile

Poison by intravenous route.When heated to decomposition it emits toxic fumes of Cr.

InChI:InChI=1/2C6H6.Cr/c2*1-2-4-6-5-3-1;/h2*1-6H;

Upstream product

• 11077-47-7 bis(benzene)chromium(I) 
• 10025-73-7 chromium(III) chloride 
• 125984-26-1 Cr(C₆H₆)2⁽¹⁺⁾*Mn(CO)5^(1-)={Cr(C₆H₆)2}{Mn(CO)5} 
• 31741-94-3 bis[(trimethylsilyl)benzene]chromium 
• 31811-69-5 {(CH₃)3SiC₆H₅}2Cr⁽¹⁺⁾ 
• 925-90-6 ethylmagnesium bromide 
• 1165952-91-9 cyclohexa-1,3-diene 
• 71-43-2 benzene 
• 143-66-8 sodium tetraphenyl borate 
• 100-58-3 phenylmagnesium bromide 
• 1234-62-4 triphenyltris(tetrahydrofuran)chromium(III) 
• 12099-15-9 bis(η6-diphenyl)chromium(0) 
• 12241-77-9 {(C₆H₆)2Cr}⁽¹⁺⁾*{OC₆H₂(NO₂)3}^(1-)={(C₆H₆)2Cr}{OC₆H₂(NO₂)3} 
• 10031-25-1 chromium(III) bromide 

Downstream Products

• 99116-67-3 diphenylbenzene chrome iodide 
• 12099-17-1 bisbiphenylchromium iodide 
• 12089-29-1 bis(benzene)chromium(I) iodide 
• 697302-50-4 (benzene)tricarbonylchromium 
• 32825-32-4 diphenylmethane tricarbonylchromium 
• 123073-40-5 {(C₆H₆)2Cr}⁽¹⁺⁾*O₂CC₆H₅^(1-)={(C₆H₆)2Cr}O₂CC₆H₅ 
• 12099-17-1 (C₆H₅C₆H₅)2CrI 
• 99116-67-3 (C₆H₆CrC₆H₅C₆H₅)I 
• 7440-47-3 chromium 
• 71-43-2 benzene 
• 199620-14-9 chromium⁽⁰⁾ hexacarbonyl 
• 26117-61-3 Cr(PF₃)6 
• 52445-45-1 (η-6-benzene)(benzoyl-η-6-benzene)chromium 
• 82556-00-1 bis(benzoyl-η6-benzene)chromium 

Related news

Electron spin resonance measurements of DIBENZENECHROMIUM (cas 1271-54-1) cation08/16/2019

ESR spectra of liquid and solid solutions of Cr(C6H6)2I have been measured. Even in solid solution the spectra show a well resolved proton hyperfine structure which is explained by rotation of the Cr(C6H6)+2 cation around its main axis. An analysis of the 53Cr hyperfine coupling constants indica...detailed

Electron paramagnetic resonance measurements of DIBENZENECHROMIUM (cas 1271-54-1) cations on silica gel and in Y-type zeolites08/12/2019

The EPR spectra of Cr(C6H6)2+ cations on silica gel and in Y-type zeolite were studied. The spectra show a well resolved proton hyperfine structure due to interactions between the unpaired electron and twelve equivalent protons of the benzene rings. An analysis of the 53Cr hyperfine structure in...detailed

Metalation of DIBENZENECHROMIUM (cas 1271-54-1) by N,N,N′N′-tetramethylethylenediamine complexes of n-butyllithium and phenyllithium08/11/2019

Dibenzenechromium is metalated by n-butyllithium in presence of TMEDA. The extent and orientation of metalation were investigated by mass spectrometric analysis of the products after quenching with D2O. A lithium substituent on dibenzenechromium strongly activates the molecule for further metala...detailed

Thermodynamic treatment of DIBENZENECHROMIUM (cas 1271-54-1) direct-synthesis reaction and its relation to decomposition reaction08/10/2019

Thermodynamic studies of the equilibrium in the direct-synthesis reaction of dibenzenechromium from benzene and chromium were carried out. The reaction of gaseous chromium with the solid ligand is shown to be the most probable mechanism of the process. The thermodynamic and kinetic stabilities o...detailed

Relevant academic research and scientific papers

Synthesis and structure of [Cr{η6-C6H 5)2B{NtBu(sime3)}}]and [Cr{(η6- C6H5)2(BNMe2)2}], the first boron-bridged metalloarenophanes

Reaction of [Cr(η6-C6H5Li) 2]·tmen with (RR′)-NBCl2 (R=R′ = SiMe3; R=R′ = iPr; R = SiMe3, R′ = tBu) and B2Br2(nmE2)2, respectively, in

Phenylchromium(III) Chemistry Revisited 100 Years after Franz Hein (Part II): From LinCrPh3+ n(thf)x(n = 1, 2, 3) to Dimeric Triphenylchromate(II) Complexes

Polyphenylchromium(III) organometallics with various phenylation degrees and stabilized by diverse Lewis bases with various donor strengths and denticity were investigated in order to better understand the formation of (η6-arene)chromium complexes according to the procedure of Franz Hein (1892-1976) [ Organometallics 2019, 38, 498-511, DOI: 10.1021/acs.organomet.8b00811]. Part II focuses on hexa-, penta-, and tetraphenylchromates(III). Chromium(III) compounds with a lower phenylation degree will be discussed in a future part III. The numbering scheme of the complexes relates to the number of Cr-bound phenyl substituents. Hexaphenylchromate(III): The reaction of Ph3Cr(thf)3·0.25dx (3) (dx = 1,4-dioxane) with an ethereal solution of phenyllithium yields yellow-orange [Li3CrPh6(thf)2.3(OEt2)0.7] (6-thf-OEt2) which slowly degrades in contact with the reaction solution leading to emerald-green crystals of [{(Et2O)Li}2Ph3Cr(μ-O)]2 (3-Li2O). Pentaphenylchromate(III): Compound 6-thf-OEt2 reacts with 1 equiv of HCl-OEt2 solution to turquoise [{(thf)2Li}{(Et2O)Li}CrPh5] (5-thf-OEt2) that reacts with THF to the green contact ion pair [{(thf)2Li}2CrPh5] (5-thf) and with 12-crown-4 (12C4) to the light green solvent-separated ion pair [(12C4)Li(thf)]2 [CrPh5] (5-thf-12C4). Refluxing of 5-thf-OEt2 in diethyl ether leads to ether degradation and formation of 3-Li2O, whereas 5-thf-12C4 liberates biphenyl under similar reaction conditions. Tetraphenylchromate(III): The reaction of 3 with 1 equiv of phenyllithium in THF leads to a green reaction mixture. At -50 °C, red [(thf)4Li] [cis-(thf)2CrPh4]·2THF (4-thf) crystallizes which reversibly transforms into a green oil above -50 °C. Upon acidolysis of 5-thf-OEt2 with 1 equiv of HCl-OEt2 at -20 °C, the intermediately formed red complex is reduced to the dinuclear chromate(II) [{(thf)Li}CrPh3]2 (3-CrII-thf) (Cr-Cr 187.66(8) pm). Recrystallization of this product from THF yields solvent-separated [(thf)4Li]2 [(CrPh3)2] (3-CrII-thf4) with a Cr-Cr quadruple bond (Cr-Cr 183.7(2) pm) without contacts between the lithium ions and Cr-bound phenyl groups. Complex 3-CrII-thf reacts at room temperature in diethyl ether to the sandwich complexes bis(biphenyl)chromium(0) [(η6-Ph2)2Cr0] (π-4) and benzene-biphenylchromium(0) [(η6-C6H6)(η6-Ph2)Cr0] (π-3). Compounds in bold letters are authenticated by X-ray structure determinations.

Synthesis and characterization of aluminum- and gallium-bridged [1.1]chromarenophanes and [1.1]molybdarenophanes

The synthesis and structural characterization of the first [1.1]chromarenophanes and the first [1.1]molybdarenophanes are described. A salt-metathesis reaction of [2-(Me2NCH2)C 6H4]AlCl2 with freshly prepared [Cr(LiC 6H5)2]·TMEDA (TMEDA = N,N,N′,N′-tetramethylethylenediamine) resulted in the dialumina[1.1]chromarenophane [{2-(Me2NCH2)-C 6H4}Al(η6-C6H5) 2Cr]2 (2a). The poor solubility of 2a in organic solvents prompted us to synthesize the new intramolecularly coordinated aluminum- and gallium dichlorides [5-tBu-2-(Me2NCH2)C6H 3]ECl2 [E = Al (3a), Ga (3b)] in which the phenyl group was equipped with a tert-butyl group. Salt-metathesis reactions of 3a and 3b, respectively, with freshly prepared [M(LiC6H5) 2]·TMEDA (M = Cr, Mo) resulted in four new [1.1]metallarenophanes of the general type [{5-tBu-2-(Me2NCH 2)C6H3}E(η6-C6H 5)2M]2 [E = Al, M = Cr (4a); E = Ga, M = Cr (4b); E = Al, M = Mo (5a); E = Ga, M = Mo (5b)]. 2a, 4a,b, and 5a,b have been structurally characterized by single-crystal analysis [2a·1/2C 6H12: C48H56Al2Cr 2N2, monoclinic, P21/c, a = 9.9117(9) A, b = 19.9361(16) A, c = 10.638(2) A, α = 90°, β = 112.322(5)°, γ = 90°, Z = 2; 4a·2C6H 6: C62H72Al2Cr2N 2, monoclinic, P21/c, a = 10.9626(9) A, b = 19.3350(18) A, c = 12.4626(9) A, α = 90°, β = 100.756(5)°, γ = 90°, Z = 2; 4b·2C6H 6: C62H72Cr2Ga2N 2, monoclinic, P21/c, a = 10.8428(2) A, b = 19.4844(4) A, c = 12.4958(2) A, α = 90°, β = 100.6187°, γ = 90°, Z = 2; 5a·2C6H6: C62H72Al2Mo2N2, triclinic, P1, a = 10.4377(4) A, b = 11.6510(4) A, c = 11.6514(4) A, α = 73.545(3)°, β = 89.318(2)°, γ = 76.120(2)°, Z = 1; 5b·2C6H6: C 62H72Ga2Mo2N2, triclinic, P1, a = 10.3451(5) A, b = 11.6752(6) A, c = 11.6900(5) A, α = 73.917(3)°, β = 89.550(3)°, γ = 76.774(2)°, Z = 1]. All five [1.1]metallarenophanes 2a, 4a,b, and 5a,b crystallize as anti isomers with both Me2N donor groups in exo positions (Ci point group symmetry). The new [1.1]metallarenophanes show NMR spectra that can be interpreted as being caused by time-averaged C2h symmetrical species, which is consistent with the findings of their molecular structures in the solid state. Variable-temperature 1H NMR measurements for 4a,b and 5a,b (500 MHz; -90 to 90 °C) revealed only peak broadening in the lower temperature range of -70 to -90 °C. 1H NMR saturation transfer difference experiments did not show an expected anti-to-anti isomerization, rendering the new [1.1]metallacyclophanes rigid on the NMR time scale. Electrochemical measurements were performed for 4a,b and 5a,b. However, reproducible cyclic voltammograms could only be obtained for the two gallium species 4b and 5b, revealing the expected weak communication between the two transition-metal atoms in both compounds (class II).

A soft-landing experiment on organometallic cluster ions: Infrared spectroscopy of V(benzene)2 in Ar matrix

Vanadium (V)-benzene cluster ions, produced by laser ablation with reaction toward benzene vapor, were size-selected and deposited into a low-temperature Ar matrix. Infrared spectrum of V1(benzene)2 in the Ar matrix was measured after one-hour deposition with the deposition energy of 20 eV. The spectrum was in agreement with both the reported spectrum and our theoretical calculations, showing that (1) V1(benzene)2, prepared in the gas-phase reaction, takes a sandwich structure and that (2) the ions were soft-landed onto the Ar matrix and were neutralized by charge transfer from a metal substrate without fragmentation.

η6-coordination of arsenine to titanium, vanadium, and chromium

By means of metal-ligand vapor co-condensation techniques the homoleptic arsenine sandwich complexes (η6-C5H5As)2Ti (2), (η6-C5H5As)2V (3), and (η6-C5H5As)2Cr (4) have been prepared. 2 is the first example of an unsubstituted group 15 heteroarene sandwich complex which yielded to full structural characterization by X-ray diffraction. The most remarkable feature of the structure of 2 in the crystal is the synperiplanar conformation and the short intramolecular interannular As?As distances which imply secondary bonding. The latter may also contribute to the packing since interannular As?As distances, which fall short of the sum of the van der Waals radii, are detected. The result of a competition experiment, in which benzene and arsenine are offered as ligands to chromium, illustrate the pronounced preference of chromium for arsenine as an η6 ligand. The mixed-ligand complexes (η6-C5H5As)(η6-C 6H6)Cr (6) and (η6-C5H5As)Cr(CO)3 (8) have also been prepared and studied spectroscopically in order to underpin the notion that arsenine, compared to benzene, is the superior η6 ligand. The study is rounded off by an investigation of the redox behavior of 2, 3, 4, and 6 (cyclic voltammetry) and by EPR measurements on 3? and 4?+. The latter confirm the pronounced π-acceptor character of η6-arsenine. This conclusion is based on the increase of the hyperfine coupling constant α(51V) upon going from bis(benzene)vanadium to the arsenine counterpart which is thought to reflect V(dz2) orbital contraction in 3?, caused by a slight increase of positive partial charge on vanadium.

Electronic properties of organometallic metal-benzene complexes [Mn(benzene)m (M = Sc-Cu)]

Neutral metal-benzene complexes, Mn(benzene)m (M = Sc to Cu), are produced for all of the 3d transition metals in the gas phase by using the laser vaporization method. These species are characterized by mass spectrometry, photoioniza

Metal π-complexes of benzene derivatives. 34. Tetraphenylsilane as a chelating ligand: Synthesis, structural characterization, and reactivity of the tilted bis(arene) metal complexes [(C6H5)2Si(η6-C 6H5)2]M (M = V, Cr)

By means of lithiation and subsequent reaction with triphenylchlorosilane and diphenyldichlorosilane, respectively, the complexes bis((triphenylsilyl)-η6-benzene)M (6, M = Cr; 8, M = V) as well as (1-6:1′-6′-n)-tetraphenylsilane)M (5, M = Cr; 7, M = V) were prepared and characterized by 1H and 13C NMR (5, 6) and EPR spectroscopies (6+, 7, 8) and by cyclic voltammetry (6-8). 5 was subjected to X-ray crystallographic analysis; the complex crystallizes in the monoclinic space group P21/n with a = 764.7 (3) pm, b = 1854.5 (8) pm, c = 1261.8 (5) pm, β = 93.60 (3)°, and Z = 4. The most pertinent features of the molecular structure of 5 are the tilting angle of the sandwich axis (165.6°), the bending of the ipso C-Si bond out of the η6-arene plane by 40.8°, and the small angle C(η-arene)-Si-C(η-arene) of 95.9°. Judging from the C-C bond lengths and 13C chemical shifts, the ipso C atoms of the coordinated arenes are in a hybridization state between sp2 and sp3. The deviation of the two η-arenes from a parallel disposition exerts a significant influence on ring proton chemical shifts, equivalent protons having the smallest interannular separations being shifted farthest upfield. For the paramagnetic vanadium analogues, EPR measurements further show that tilting is accompanied by an increase in metal → ligand spin delocalization. The single-atom-bridged tilted complexes 5 and 7 are labile in solution. Whereas for the chromium species 5 protodesilylation to yield unsubstituted bis(benzene)chromium (9) dominates, the vanadium species 7 undergoes metal-ligand cleavage. Tilting exerts only a minor influence on the redox potential since E1/2 for the couple 70/- lies approximately halfway between the E1/2 values for 1-Ph3Si- and 1,1′-(Ph3Si)2-substituted bis(benzene)-vanadium.

Metall-?-Komplexe von Benzolderivaten. XXXV. Bis(η6-bimesityl)chrom. Magnetische Abschirmung und konformative Beweglichkeit

Metal-atom ligand-vapor cocondensation affords the complexes bis(η6-bimesityl)chromium (2), (η6-bimesityl)(η6-benzene)chromium (5) and bis(η6-2,4,8,10-tetramethylbiphenyl)chromium (4), and conventional carbonyl substitution yields the compounds (η6-bimesityl)(tricarbonyl)chromium (7) and μ(ν6 : η6-bimesityl)bis (8). 1H NMR data for 2 suggest that in the rotamer of lowest energy the two bimesityl ligands with regard to the sandwich axis have a twist angle, α, of about 90 of 270 deg, respectively.These two rotamers undergo torsional interconversion with an activation barrier of ΔGc 75 kJ/mol.The 1H NMR spectra of 2, 5, 7 and 8 are assigned and the large chemical shift differences are traced to the unique positions the protons adopt in the periphery of the bis(η6-arene)metal core.The NOE difference spectrum of 2 is temperature dependent; rapid exchange on the T1 scale is achieved at 53 deg C, a temperature at which, on the chemical shift time scale, slow exchange still prevails.In 4, the ortho-methyl groups of the 8,10-dimethyl substituent relative to the central metal, exclusively occupy exo-positions.Correspondingly, the activation barrier for the conformational interconversion is decreased in 4 compared to 2.Owing to the lower symmetry of the ligand o,o',p,p'-tetramethylbiphenyl (3), the binary complex (3)2Cr is formed as a mixture of the forms meso-4 and rac-4.Although 4 is already in the fast exchange region at room temperature, the 1H NMR spectrum still displays a marked temperature dependence.The latter is caused by the fact that for meso-4 the two equilibrating rotamers are enantiomers, whereas for rac-4 they are diastereomers.Thus, in contrast to meso-4, for rac-4 the population ratio of the two interconverting rotamers is temperature dependent.

Metal ? Complexes of Heteroarenes, II. - η6-Coordination of Unsubstituted Pyridine: (η6-Benzene)(η6-pyridine)chromium and Bis(η6-pyridine)chromium

Three-component cocondensation of benzene, pyridine, and chromium affords (η6-benzene)(η6-pyridine)chromium (5), the first bis(arene)metal complex of unsubstituted pyridine.The binary complex bis(η6-pyridine)chromium (7) is obtained by desilylation of bis6-pyridine>chromium (6), the latter being accessible through cocondensation techniques.The function of the trimethylsilyl groups is to sterically block the pyridine N atoms thereby assuring η6-coordination in the first step.The new compounds 5 - 7 are characterized by means of 1H and 13C NMR, MS, ESR (radical cations), and cyclic voltammetry.According to X-ray diffraction, crystals of 5 are disordered such that individual molecules exist in the lattice as synclinal or/and antiperiplanar rotamers. 5 can be protonated at nitrogen.The value of pKS (5-H+), determined from the pH dependence of the UV spectrum and of the redox potential for the couple 5 0/+, reveals that η6-pyridine in 5 is more basic by 2.5 - 3.0 pK units than free pyridine.