Reactions with Co and

My early work with acyl fluorides also involved formyl fluoride, ITCOF, the only stable acyl halide of formic acid, which was first made in 1933 by Nyesmeyanov, who did not, however, pursue its chemistry. 1 developed its use as a formylating agent and also explored formyla-tion reactions with CO and HF, catalyzed by BF3. 

Diglycolamine Systems. The Fluor Econamine process uses digl> co lamine (DGA) to sweeten natural gas. The active DGA reagent is 2-(2-tunino-ethoxy) ethanol, w hich is a primary amine. The reactions of DG, with acid gases are the same as for MEA. Degradation products from reactions with COS and CS2 can be regenerated in a reclaimer. 

For DEA systems a reclaimer is not required because the reactions with COS and CS2 are reversed in the stripper. The small amount of degradation products from COo can be removed by a carbon filter on a side stream of lean solution. 

The bluish white, hard, yet ductile, metal is inert to all acids and highly non-abrasive. Used for heavy-duty parts in electrical contacts and spinning jets. Reflectors are prepared from the mirror-smooth surfaces (e.g. head mirrors in medicine). Thin coatings provide a corrosion-resistant protective layer, for example, for jewelry, watches, and spectacle frames. The metal is a constituent of three-way catalysts. Rhodium complexes are used with great success in carbonylations (reactions with CO) and oxidations (nitric acid) in industry. Platinum-rhodium alloys are suitable thermocouples. 

This is one of the simplest systems for which isomers can exist. Ab initio calculations of the energetics for this system have shown that HCN+ is 17.7 kcal mol-1 less stable than HNC+ and has an energy barrier to isomerization of 30.9 kcal mol-1. Even though this barrier is substantial, isomerization occurs in the reactions with CO and C02, in parallel with a small proton transfer channel,23 viz.,... 

The two major tropospheric sinks of OH are the reactions with CO and CH4. In the clean Southern Hemisphere, CO and CH4 account for up to 50% each of the total OH loss, and HO2 and CH3O2 are the predominant forms of peroxy radicals formed (Reactions 3, 4, respectively). 

In remote marine regions where there are not significant sources of large, biogenic VOCs, OH is removed by reaction with CO and CH4 ... 

The relationship between the peroxy radical concentration and the ozone photolysis rate constant for these higher NO conditions can be again approximated using steady-state analysis (Penkett et al., 1997 Carpenter et al., 1997). While OH is recycled in its reactions with CO and CH4 via H02, it is permanently removed at higher NOx concentrations by the reaction of OH with N02, forming nitric acid ... 

Similarily, styrene and 4-isobutylstyrene were converted to the corresponding carboxylic acids (Equations 4 and 5) by reaction with CO and H20 in the presence of Pd(tppts)3 and p-CH3C6H4S03H (no organic solvent) at 65°C and 50-140 bar CO (the relatively low temperature is required to suppress polymerization of the substrate). The major products were the branched acids in both cases 90% and 74% with styrene and 4-isobutylstyrene, respectively. In the case of 4-isobutylstyrene the branched acid product is the anti-inflammatory drug ibuprofen. 

The complex reacts readily with ligands such as tertiary phosphines, phosphites, or arsines to give substitution of a CO ligand on the cobalt atom. With CO, however, the complex reacts to give 2-phenylindazolone and 3-phenyl-2,4 lif, 3f/)-quinazolinedione,15 whereas the reaction with CO and hexafluoro-2-butyne affords an anilinoquinoline, probably via an intermediate complex in which the alkyne and CO have inserted into the Co—C bond.16... 

The preparation of fulminate (CNO) and isocyanate (NCO) complexes, and their reactions, have been reported.17 These include the conversion of [Pd(NCO)2(PPh3)2] to [Pd(NC0)(C02R)(PPh3)2 on reaction with CO and ROH (R = Me, Et). 

We have mentioned that the structural parameters of C2H4 bridged compounds can vary over a wide range. Whereas most examples reported do not have metal-metal bonds, there is one conspicuous exception. Theopold and Bergman succeeded in synthesizing the propane-1,3-d iyl cobalt derivative 125 from the radical anion [(t) ,-C5H5)Co(/z-CO)12 and 1,3-dibromopropane (98, 295) in 40 5 yield. This compound is best described as a dimetallacyclopentane, and its chemistry (thermolysis and reaction with CO and phosphines Scheme 34) supports this view. Formation of cyclopropane (100°C or I2/25°C) is probably the most remarkable feature of this cyclic system. Simple C—C bond formation has never been observed before in ligand-induced or thermal reactions of either mono- or binuclear cyclopentadienylcobalt complexes. The architectural details of... 

The second class of reactions, with CO and H20 serving as a source of two electrons, is not a catalytic reaction as such but is examined closely here since this is an integral step in the homogeneous catalysis of the water gas shift. The reaction may take two forms, with the reduction product being either a reduced metal center, (29), or a metal hydride, (30). 

Using (E) -alkenylpentafluorosilicates, unsaturated esters can be readily obtained by reaction with CO and methanol (equation 127).523 PdCI2 or PdBr2 was generally effective as catalyst. Complex (106) was less satisfactory and no carbonylation occurred with [PdCl2(PPh3)2] (102). 

Directly supported clusters of type Os3H(CO)10(O—metal oxide) break down at quite low temperatures to give species which have a high selectivity to methane from CO and H2 (381,400). Similar behavior has been reported for Os3(CO)12 itself (401), but it is difficult to rule out metal as the catalyst. Os3(CO)12 also leads to methanol, methyl and ethyl formate, and acetone by reaction with CO and H 2 (190° C, 180 atm) in glyme solvents (402). The water-gas-shift reaction is catalyzed by Os3(CO)12, using KOH or even sodium sulfide in methanol as the base (403), although ruthenium catalysts are better (404). 

Methoxy carbony lotion. Aryl triflates or iodides are converted into alkyl benzoates by reaction with CO and an alcohol at 70° catalyzed by Pd(OAc)2 in combination with dppp yields are 72-95%. The method is useful for esterification of phenols under mild conditions.2... 

The dominant loss of OH radicals is reaction with CO and organic compounds such as CH4, both reactions produce peroxy radicals. Peroxy radicals play a key role in atmospheric chemistry. They are intimately involved in the formation and destruction of ozone and in the photooxidation of all organic compounds in the atmosphere [4], The lifetime of OH radicals with respect to reactions Eq. 3 and Eq. 8 is of the order of a second and in the day-time a steady state condition is established. The OH radical concentration in the atmosphere varies with location, time of day, season, and meteo-... 

The reactions of HNCC with the nucleophiles X and [NO 2] are treated separately because they may either lead to the formation of reduced species, as discussed in Section or follow the same trends as the reactions with CO and PR 3 discussed above. The outcome of the reaction seems to depend on the nature of the individual cluster considered. For example, simple addition of iodide with opening up of the metal polyhedron has been observed in the formation of [Os5C(CO)i5l] and [Os5(CO)ijH2l] (65, 76) from OssC(CO)i5 and Os5(CO)ijH2, respectively. Alternatively, reaction of this nucleophile with Rh6(CO)ig results in the formation of the substituted products [Rh6(CO)i5l] and [Rh6(CO)i4l2] (Scheme 37). In contrast, the binary carbonyls Os (CO) (m = 6, 7, 8 n = 18, 21, 23) are reduced to their respective dianions (Section II,C,2), while the hydrido clusters Os (CO) H2 (m = 6,7,8 n = 18,20,22) are deprotonated by halides (Section II,B). 

An example of a homogeneous WGS catalyst is Rht(CO)i2 in aqueous pyridine.51 Analogous reactions with CO and alcohols instead of water are also known.52 Some important reactions of CO, H2, and methanol are shown in Fig. 22-5. 

Homogeneous transition metal catalysts, in a broad sense, are offsprings of the field of organometallic complex chemistry. Here complexes and reactions with CO and H are among the most studied areas. A wealth of information is available. 

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