II Perchlorate

I Caution. Perchlorate salts of complexes can be explosive and should be handled with care in a fume hood and behind a protective shield. They should not be heated as solids or as concentrated solutions. 

A solution of barium perchlorate trihydrate (1.96 g, 0.005 mole) in 300 mL of methanol is placed in a 500-mL conical flask and heated to 50°. To this warm solution is added 1.37 g (0.01 mole) of freshly sublimed 2,6-pyridinedicarbox-aldehyde, followed by 1.20 g (0.01 mole) of 1,2-benzenediamine (after puri- 

BENZO[6,/fI][l,4,12,15]TETRA-AZACYCLODOCOSINE-PERCHLORATOCADMIUM(n) PERCHLORATE MeOH 

To a suspension of 1.17 g (0.001 mole) of [BaL2 ](C104)2 in 500 mL of methanol in a 1-L round bottomed flask fitted with a reflux condenser is added 1.67 g (0.004 mole) of solid cadmium(II) perchlorate hexahydrate. The mixture 

[meso- and racem/c-(5,7,7,l2,14,14-HEXAMETHYH,4,8,ll-TETRAAZA-CYCLOTETRADECA-4,11-DIENE]NICKEL(II) PERCHLORATE 

Nickel diacetate tetrahydrate (103 g,0.42 mole) is dissolved in 1.5L of methanol in a 3-L beaker and the ligand Meg [14]-4,1 l-dieneN4 2HC104 (180 g, 

Because of the restricted inversion of the asymmetric secondary amine functions, nickel(ll) complexes of Meg[14]-4,1 l-dieneN4 can exist in both the meso and racemic forms, which can be interconverted in solution. The diaster-eoisomers have been distinguished by optical rotation and NMR studies. The NMR spectra show three equally intense resonances (at 2.67, 2.52 and 1.75 ppm for the racemic thiocyanate salt and at 2.69, 2.21, and 1.75 ppm for the meso thiocyanate salt in D2O) assignable to the pairwise equivalent imine methyl groups (equatorial orientation) and to the axial and equatorial geminal methyl groups, respectively. The diastereoisomers each exhibit a single electronic absorption maximum between 21.0 and 23.0 and infrared bands near 

BIS(ACETONITRILE)(5,7,7,12,14.14-HEXAMETHYL-l,4,8,11-TETRA-AZACYCLOTETRADECA-4,1 l-DIENE)IRON(II) TRIFLUORO-METHANESULFONATE 

The infrared spectrum of the complex shows a very intense N—H stretching absorption at about 3220 cm and an intense imine C=N stretching absorption in the 1670-1640 cm region. 

---

Copper(II) perchlorate, Cu(CI04)2,6H20. Formed from CuO and HCIO4. 

Perchlorates. Iron(II) perchlorate hexahydrate [13922-23-8], Fe(C10 2 6H20, is prepared by dissolving iron in cold, dilute perchloric acid or by dissolving FeS in perchloric acid. It crystallizes in hygroscopic, light green hexagonal prisms which are stable in dry air and extremely soluble (0.978 g/mL H2O at 0°C) in water and alcohol. It is susceptible to air oxidation in aqueous solution and decomposes above 100°C. Yellow iron(III) perchlorate... 

CuClO, and copper(II) perchlorate [13770-18-8] Cu(Cl04)2, form a number of complexes with ammonia, pyridine, and organic derivatives of these compounds. The copper perchlorate is an effective bum-rate accelerator for soHd propellants (39). 

Group 12 (IIB) Perchlorates. The zinc perchlorate [13637-61 -17, cadmium perchlorate [13760-37-7] mercury(I) perchlorate [13932-02-0] and mercury(II) perchlorate [7616-83-3] all exist. Cell potential measurements show that zinc and cadmium perchlorates are completely dissociated in concentrations up to 0.1 molar in aqueous solutions (47—49). Mercurous perchlorate forms a tetrahydrate that can be readily converted to the dihydrate on heating to above 36°C (50). 

Cationic complexes of rran.s-chelating tridentate ligand, (/ ,/ )-4,6-dibenzo-furandiyl-2,2 -bis(4-phenyloxazoline), with transition metal(II) perchlorates as effective catalysts for asymmetric cycloaddition of nitrones 98YGK368. 

The cationic aqua complexes prepared from traws-chelating tridentate ligand, R,R-DBFOX/Ph, and various transition metal(II) perchlorates induce absolute enantio-selectivity in the Diels-Alder reactions of cyclopentadiene with 3-alkenoyl-2-oxazoli-dinone dienophiles. Unlike other bisoxazoline type complex catalysts [38, 43-54], the J ,J -DBFOX/Ph complex of Ni(C104)2-6H20, which has an octahedral structure with three aqua ligands, is isolable and can be stored in air for months without loss of catalytic activity. Iron(II), cobalt(II), copper(II), and zinc(II) complexes are similarly active. 

The nickel and cohalt aqua complexes were even more effective, both for catalytic activity and enantioselectivity, than the corresponding anhydrous complexes (Scheme 7.5). Addition of three equivalents of water to the anhydrous nickel complex recovered the catalytic efficiency. DBFOX/Ph complexes derived from manga-nese(II), iron(II), copper(II), and zinc(II) perchlorates, both anhydrous and vef. 

Among the J ,J -DBFOX/Ph-transition(II) metal complex catalysts examined in nitrone cydoadditions, the anhydrous J ,J -DBFOX/Ph complex catalyst prepared from Ni(C104)2 or Fe(C104)2 provided equally excellent results. For example, in the presence of 10 mol% of the anhydrous nickel(II) complex catalyst R,R-DBFOX/Ph-Ni(C104)2, which was prepared in-situ from J ,J -DBFOX/Ph ligand, NiBr2, and 2 equimolar amounts of AgC104 in dichloromethane, the reaction of 3-crotonoyl-2-oxazolidinone with N-benzylidenemethylamine N-oxide at room temperature produced the 3,4-trans-isoxazolidine (63% yield) in near perfect endo selectivity (endo/exo=99 l) and enantioselectivity in favor for the 3S,4J ,5S enantiomer (>99% ee for the endo isomer. Scheme 7.21). The copper(II) perchlorate complex showed no catalytic activity, however, whereas the ytterbium(III) triflate complex led to the formation of racemic cycloadducts. 

Methylamine Cupric Perchlorate Complex. (MeNH2)4Cu(Cl04)2, C4H2od2C uN408, mw 386.72, N 14.49%. It is prepd by the interaction of methylamine and Cu(II)perchlorate and is obtd as blue crysts which expld in 30secs at 247°... 

Transient concentrations of Ag(II) were detected spectrophotometrically, and by electron spin resonance. The thermal decomposition of Ag(II) perchlorate, the subject of a separate studytakes place by... 

The ready oxidation of di-isopropyl ether by Hg(II) perchlorate " is a good indication that this oxidant can function as a hydride-ion acceptor, viz. 

The rate expression for the oxidation of water by silver(II) perchlorate, [Ag(II)] [C104-] ... 

With palladium (II) perchlorate, triethylphosphine gives rise to an explosive complex, if it is heated, even moderately ... 

Redox titrants (mainly in acetic acid) are bromine, iodine monochloride, chlorine dioxide, iodine (for Karl Fischer reagent based on a methanolic solution of iodine and S02 with pyridine, and the alternatives, methyl-Cellosolve instead of methanol, or sodium acetate instead of pyridine (see pp. 204-205), and other oxidants, mostly compounds of metals of high valency such as potassium permanganate, chromic acid, lead(IV) or mercury(II) acetate or cerium(IV) salts reductants include sodium dithionate, pyrocatechol and oxalic acid, and compounds of metals at low valency such as iron(II) perchlorate, tin(II) chloride, vanadyl acetate, arsenic(IV) or titanium(III) chloride and chromium(II) chloride. 

Precipitation titrants include silver nitrate (in methanol or ethanol) and mercury(II) perchlorate (in glacial acetic acid). 

EXAMPLE 6.13. Write the formulas for ( ) copper(II) perchlorate and (6) sodium sulfite. 

Some of the products of interaction of acetaldehyde and mercury(II) chlorate or mercury(II) perchlorate are highly explosive and extremely shock-sensitive. 

See Chromium(III) perchlorate. 6 dimethyl sulfoxide Magnesium perchlorate Dimethyl sulfoxide Mercury(II) perchlorate. 6(or 4)dimethyl sulfoxide Silver perchlorate Dimethyl sulfoxide See Perchloric acid Sulfoxides... 

Dining dehydration of manganese(II) perchlorate [1] or nickel(II) perchlorate [2] with dimethoxypropane, heating above 65°C caused violent explosions, probably involving oxidation by the anion [1] (possibly of the methanol liberated by hydrolysis). Triethyl orthoformate is recommended as a safer dehydrating agent [2] (but methanol would still be liberated). 

Bromo-5,7,7,12,14,14-hexamethyl-l,4,8,ll-tetraaza-4,H-cyclo-tetra decadieneiron(II) perchlorate... 

---