Zirconium peroxides

Lead Ammonium nitrate, chlorine trifluoride, hydrogen peroxide, sodium azide and carbide, zirconium, oxidants... 

Lead dioxide Aluminum carbide, hydrogen peroxide, hydrogen sulfide, hydroxylamine, ni-troalkanes, nitrogen compounds, nonmetal halides, peroxoformic acid, phosphorus, phosphorus trichloride, potassium, sulfur, sulfur dioxide, sulfides, tungsten, zirconium... 

Zirconium carbide is inert to most reagents but is dissolved by hydrofluoric acid solutions which also contain nitrate or peroxide ions, and by hot concentrated sulfuric acid. Zirconium carbide reacts exothermically with halogens above 250°C to form zirconium tetrahaHdes, and with oxidizers to zirconium dioxide in ak above 700°C. Zirconium carbide forms soHd solutions with other transition-metal carbides and most of the transition-metal... 

The hydrides can also be used to form primary alcohols from either terminal or internal olefins. The olefin and hydride form an alkenyl zirconium, Cp2ZrRCl, which is oxidized to the alcohol. Protonic oxidizing agents such as peroxides and peracids form the alcohol direcdy, but dry oxygen may also be used to form the alkoxide which can be hydrolyzed (234). 

Borides are inert toward nonoxidizing acids however, a few, such as Be2B and MgB2, react with aqueous acids to form boron hydrides. Most borides dissolve in oxidizing acids such as nitric or hot sulfuric acid and they ate also readily attacked by hot alkaline salt melts or fused alkaU peroxides, forming the mote stable borates. In dry air, where a protective oxide film can be preserved, borides ate relatively resistant to oxidation. For example, the borides of vanadium, niobium, tantalum, molybdenum, and tungsten do not oxidize appreciably in air up to temperatures of 1000—1200°C. Zirconium and titanium borides ate fairly resistant up to 1400°C. Engineering and other properties of refractory metal borides have been summarized (1). 

Group 1 Chlorate and metal perchlorate report or whistling compositions Dry non-gelatinized cellulose nitrates Barium peroxide/zirconium compositions Burn very violently Flash shells (maroons) Casings containing flash compositions Sealed hail-preventing rockets Mass explosion risk... 

Lead oxide reacts violently with numerous metals such as sodium powder (immediate ignition), aluminium (thermite reaction, which is often explosive), zirconium (detonation), titanium, some metalloids, boron (incandescence by heating), boron-silicon or boron-aluminium mixtures (detonation in the last two cases). Finally, silicon gives rise to a violent reaction unless it is combined with aluminium (violent detonation). It also catalyses the explosive decomposition of hydrogen peroxide. 

Iodoform Iodomethane Iron disulfide Isothiourea Ketones Lactonitrile Lead Acetone, lithium, mercury(II) oxide, mercury(I) chloride, silver nitrate Silver chlorite, sodium Water, powdered pyrites Acrylaldehyde, hydrogen peroxide, nitric acid Aldehydes, nitric acid, perchloric acid Oxidizing materials Ammonium nitrate, chlorine trifluoride, hydrogen peroxide, sodium azide and carbide, zirconium, oxidants... 

A combination of axially chiral C2-symmetric binaphthol 85 with Zr(OBu-f)4 and TBHP represented a novel access to asymmetric BV oxidation. The system works under stoichiometric conditions and leads to the formation of the zirconium species 113, responsible for the activation of ketone and, likely, of the peroxide . As an example, the BV oxidation of 114 afforded the lactones 115 and 116 in a ratio 1 5 with 84% and 14% ee, respectively (equation 80). Asymmetric inductions are preserved also if one of the two chiral diols coordinated to zirconium is replaced with conformationally flexible biphenols . 

Zirconium(IV) complexes hydrogen peroxide determination, 635-6 olefin epoxidation, 417, 419, 422 Zwitterions... 

F) K.K. Andreev, "Termicheskoye Razlo-zheniye i Goreniye Vzryvchatykh Veshchestv (Thermal Decomposition and Combustion of Explosive Substances), GosEnergoIzdat, Moscow(1957) G) P. Breisacher et al, "Flame Front Structure of Lean Diborane-Air and Diborane-Hydrocarbon-Air Mixtures", 7thSympCombstn(1959), PP 894-902 H) M. Getstein, "A Study of Alkylsilane Flames , Ibid, pp 903-05 I) P.L. Harrison, "The Combustion.of Titanium and Zirconium , Ibid, pp 913-20 J) J.D. Lewis A.C, Merrington, "Combustion of n-Heptane Spray in the Decomposition Products of Concentrated Hydrogen Peroxide , Ibid, pp 953-57... 

SELECTIVE OXIDATION OF SULFIDES TO SULFOXIDES AND SULFONES USING HYDROGEN PEROXIDE IN THE PRESENCE OF ZIRCONIUM TETRACHLORIDE... 

Compound Name Barium Peroxide Bismuth Oxychloride Zirconium Oxychloride Sulfuric Acid Benzene Hexachloride Oil Spindle Sucrose... 

The incorporation of vanadium(V) into the framework positions of silicalite-2 has been reported by Hari Prasad Rao and Ramaswamy469. With this heterogeneous oxidation catalyst the aromatic hydroxylation of benzene to phenol and to a mixture of hydroquinone and catechol could be promoted. A heterogeneous ZrS-1 catalyst, which has been prepared by incorporation of zirconium into a silicalite framework and which catalyzes the aromatic oxidation of benzene to phenol with hydrogen peroxide, is known as well in the literature. However, activity and selectivity were lower than observed with the analogous TS-1 catalyst. 

They can be handled analogous to thermosetting resins, and thus the use of highly volatile comonomers, such as ethene or prop-ene is prohibitive. Instead, other vinyl monomers are used. A heat curable formulation uses a mixture of tetracyclododecene, 2-norbomene, 5-vinyl-2-norbomene, and divinylbenzene as reactive components (41). The mixture further contains 3,5-di-ferf-butylhy-droxyanisole as antioxidant and a hybrid catalyst system containing a zirconium based metathesis catalyst and a radical catalyst. The metathesis catalyst is benzylidene (l,3-dimesitylimidazolidin-2-yl-idene)(tricyclohexylphosphine)ruthenium dichloride and the radical catalyst is di-ferf-butyl peroxide. 

A variety of peroxo and hydroperoxo complexes of zirconium(IV) and hafnium(IV) have been isolated from aqueous or aqueous methanolic hydrogen peroxide solutions that contain additional ligands such as sulfate, oxalate or fluoride. Examples of recently reported complexes are listed in Table 8 along with characteristic vibrational frequencies and the pH employed in the aqueous preparations. Earlier work on peroxo compounds has been reviewed by Connor and Ebsworth180 and by Larsen.5... 

Some polysiloxanes are curable with lead monoxide, with a consequent reduction in both curing time and temperature. High-frequency electrical energy vulcanizes in one case at least. Zirconium naphthenate imparts improved resistance to high temperatures. Barium salts are said to prevent blooming. Sulfur dichloride is also used. Some resins are solidified by pressure vulcanization, using di-f-butyl peroxide. Improvements are to be found in lower condensation temperatures and shorter times of treatment... 

This type of complex is derived from the mononuclear superoxo species via a further one-electron reduction of the dioxygen moiety. Cobalt is the only metal to form these complexes by reaction with dioxygen in the absence of a ligating porphyrin ring. Molybdenum and zirconium form peroxo-bridged complexes on reaction with hydrogen peroxide. In most cases the mononuclear dioxygen adducts of cobalt will react further to form the binuclear species unless specific steps are taken to prevent this. 

In the Halcon epoxidation process, the reaction of the zirconium(IV) methyl trialkoxide (201) with 02 yields the epoxy alkoxide (203), via intramolecular epoxidation of the coordinated allyl alcohol by the incipient methyl peroxide complex (202).630... 

Antimony sulfide Tetracene Calcium silicide Lead dioxide Aluminum powder Ground glass Lead hypophosphite Lead peroxide Zirconium Nitrocellulose Pentaerythritol tetranitrate Gum type binder... 

Zirconium-aryne complexes have also found application in the regiose-lective synthesis of halophenols.62 Reaction of 101 with methyl diethylbori-nate or triethylborate leads to insertion of a boron-oxygen bond into a Zr-benzyne bond with formation of 102 and 104, respectively (Scheme 12). Further reactions of 102 and 104 with bromine or iodine followed by excess NaOH and 30% hydrogen peroxide gives halomethyl(methoxy)phe-nols 103 and 105 in good yields. In most cases only one regioisomer of the halophenol was observed. 

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