OC, Carbon monoxide

OC, Carbon monoxide chromium complex, 21 1, 2 chromium and tungsten complexes, 23 27 cobalt complex, 25 177 cobalt complexes, 23 15-17, 23-25 cobalt, iron, osmium, and ruthenium complexes, 21 58-65 cobalt-osmium complexes, 25 195-197 cobalt-ruthenium cluster complexes, 25 164... 

OC, Carbon monoxide, chromium complex, 21 1, 2 chromium and tungsten complexes, 23 27 cobalt complexes, 23 15-17, 23-25... 

OC, Carbon monoxide (Continued) cobalt, iron, osmium, and ruthenium complexes, 21 58-65 iron complex, 21 66, 68 manganese complexes, 23 34 molybdenum complexes, 23 4-9 niobium complexes, 23 34 palladium complex, 21 49 rhodium complexes, 23 124 ruthenium complex, 21 30 OCH4, Methanol, iridium complexes, 23 127 rhodium complexes, 23 127, 129 OCjHs, Acetone, compd. with carbonyltri-p.-chloro-chlorotctrakis-(triphenylphosphine)diruthcnium (1 2), 21 30... 

FAS is normally characterized by growth retardation, anomalies of the head and face, and psychomotor dysfunctions. Excessive consumption of ethyl alcohol may lead to malformations of the heart, extremities, and kidneys. Since consumption of ethyl alcohol is socially acceptable and prevalent even in pregnant women, the risks associated with the use of ethyl alcohol are remarkable. However, it should be kept in mind that there are several chemical compounds in tlie occupational environment that may also cause malformations even at low doses. The oc-cupationally-important known human teratogens include methyl mercury, ethyl alcohol, PCB compounds, tobacco smoke, lead, TCDD, 2,4,5- F, carbon monoxide, nitrogen dioxide, gasoline, and fluoride. 

The BH3 molecule is not stable as a separate entity. This molecule can be stabilized by combining it with another molecule that can donate a pair of electrons (indicated as ) to the boron atom to complete the octet (see Chapter 9). For example, the reaction between pyridine and B2H6 produces C5H5N BH3. Another stable adduct is carbonyl borane, OC BH3 in which a pair of electrons is donated from carbon monoxide, which stabilizes borane. In CO, the carbon atom has a negative formal charge, so it is the "electron-rich" end of the molecule. Because the stable compound is B2H6 rather than BH3, the bonding in that molecule should be explained. 

Lewis bases having two or more lone-pair-bearing atoms can exhibit a form of isomerism in H-bonding. This can be illustrated most simply with carbon monoxide, which has sigma-type lone pairs both on C and on O, and thus is expected to form n—>-cr H-bonds of either OC HA or CO HA type with a hydride-bearing Lewis acid. For example, complexation of CO with HF gives rise to distinct OC- -HF or CO- -HF complexes.39 The two possible isomeric forms are shown in Fig. 5.3, both bound by rather typical H-bond energies ... 

No improvement in yield was achieved in a reagent preparation carried out under an atmosphere of carbon monoxide rather than nitrogen. The mechanism of this conversion of ClCCo3(CO)9 to the (OC)9Co3CCO+ ion is of interest, especially since this reagent is preparatively useful. The aluminum chloride is essential in order to obtain good product yields. 

Importantly, a Friedel-Crafts formylation has not yet been successful. Formyl chloride and formic anhydride are not stable reagents. The mixed anhydride H—C(=0)—O—C(=0)CH3 acts as a formylating reagent in reactions with many nucleophiles (cf. Section 6.3.3). However, in reactions with aromatic compounds under Friedel-Crafts conditions, it acts as an acetylating agent rather than as a formylating agent. Last but not least, formic acid and mineral acids proceed to react via the acylium ion H—C=0 to form carbon monoxide and water in an OC-elimination. We ll solve this problem later. 

Until recently, isolable CO complexes of silver were unknown. However, if the counteranion possesses only very weak basicity, fairly stable CO adducts are obtained. Carbon monoxide acts in these compounds as a donor ligand only. Back-bonding is virtually absent, and the C—O stretching frequencies are substantially higher than that of free CO (2143 cm"1). The compounds [Ag(CO)]+X" (vqo = 2204 cm"1) and [OC—Ag—CO]+X (vco = 2198 cm-1) [X = B(OTeF5)4] were characterized by X-ray diffraction.21 The [Ag(CO)3]+ ion is formed under CO pressure. 

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