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Oscillatory carbonylation of phenylacetylene in the absence of externally supplied oxidant

“…The induction period observed prior to entering the oscillatory region is considerably shorter than the 2,000 min recorded previously at similar temperatures [17]. Temkin and co-workers [6,8] were able to achieve oscillations in pH within minutes of starting a PCPOC reaction, however they reported an experimental setup using mixed gases (CO/O 2 ) and higher reaction temperatures (40°C). The behavior reported in the present study was observed at higher catalyst loadings, using pre-dried solutions and without an external supply of oxygen to recycle the catalyst.…”

“…The oxidative carbonylation of phenylacetylene (PCPOC reaction) using PdI 2 , KI, O 2 and NaOAc in methanol was shown to display oscillations in pH, redox potential and the rate of consumption of a CO-O 2 gas mixture [6,7]. Substrates such as methylacetylene and 2-methyl-3-butyn-2-ol display similar oscillatory behavior [8]. More recent studies of the PCPOC reaction using power compensation calorimetry confirm synchronized oscillations in reaction exothermicity and pH.…”

Alkynes Carbonylation Reactions in Solutions of Palladium Complexes as a New Class of Oscillatory Processes

“…First, it is connected with the proximity of the systems (palladium compounds as catalyst; methanol and acetone as solvents) to these ones, in which we had found oscillations in the earlier works [14][15][16][17]. Second, in system of MA and SA synthesis it is revealed, as we believe, the phenomenon of bistability, and from the literature it is known, that in the systems having of bistability, realization of transition to self-oscillations is quite possible.…”

“…2 are close to that were observed by us for other systems including PhA, MAc and DMEC as substrates. It can testify to the common features for these systems of the reaction mechanisms, which have offered as an explanation of oscillations occurrence in the systems with PhA and MAc [14][15][16] (for example, HPdI participation in the process, or interruption of a chain of steps by an oxidant formed during the process-the availability of a feedback).…”

“…Further it has been shown, that the reaction of oxidative carbonylation of phenylacetylene (ethynylbenzene) (PhA) [14,15], methylacetylene (1-propyne) (MAc) [16] and dimethylethinylcarbinol (2-methyl-3-butyn-2-ol) (DMEC) [17] in a system PdI 2 -KI-MeOH-O 2 with the formation of mainly a, b-non-saturated acids diesters proceeds in an oscillatory mode (change of E Pt , pH, and reaction rate). In other catalytic systems (PdBr 2 -LiBr) we found the chaotic oscillations by using of PhA, and new oscillatory reaction of PhA and MAc oxidative carbonylation to phenylmaleic (3-phenyl-2,5-furandione) and citraconic (3-methyl-2,5-furandione) anhydrides, accordingly, in the system PdBr 2 -LiBr-CH 3 COCH 3 -H 2 O, O 2 being used as an oxidant [18].…”