Formaldehyde, Carbonyl Halides, etc

Formaldehyde, Carbonyl Halides, etc. The production of thioformaldehyde monomer, by direct photolysis of thietan vapour, has been reported. Also studied is a method whereby the monomer may be trapped and analysed quantitively via its reaction with cyclopentadiene.  

X2CY (X = F or Cl Y — O or have been undertaken. Furthermore, the geometries of H2CO, ° H2CS, and their protonated derivatives H2COH and H2CSH, and of the radical have been predicted from theoretical calcula- 

The theoretically derived geometry of HCO has been compared to that measured experimentally. The OCH bond angles (128.0 and 127.4 , respectively) agree closely whereas r(C—H) is calculated (1.100 A) to be shorter than experimentally determined (1.110 A), the calculated r(C—O) value (1.180 A) is larger than the experimental value (1.171 A). The theoretician finds this latter observation astonishing, and, based on previous correlations between theoretical and experimental bond distances, whould predict a real bond length of 1.195 A, ca. 0.015 A larger than the calculated value. 

The structure Of FCICS has been determined by Ziel et al, using both microwave and electron-diffraction techniques. The two sets of data (Table 9) are in excellent agreement, confirming the planar structure. 

The oxidation of H2CO has been the subject of a number of recent communications both kinetic and thermodynamic factors are assessed. Ion-molecule chemistry in H2CO and in H2CO-NH3 mixtures has also been investigated, using I.C.R. techniques. 

Formaldehyde and its Substituted Derivatives.—Formaldehyde, Carbonyl Halides, etc. Despite the general decrease in the number of publications in this field, the high proportion describing the spectroscopic properties of these molecules has been maintained these, together with the corresponding publications for formic acid and formates, are collected in Table 9. The 

Thermal decomposition of H2CO in the presence of NO has been studied at 500 °C.159 The results indicate that the pyrolysis is initiated by reaction (33) and involves the chain-carrying step (34). 

18F exchange between F2CO and Group I fluorides (LiF—CsF) has been studied to ascertain the effect of dipolar aprotic solvents.160 Exchange varies in the order Cs Rb K Na, Li at 423 K (Cs Rb K, Na, Li at 323 K), and is enhanced in the presence of acetonitrile or diglyme but not benzene or ether. 

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