Synthesis of HCN Polymer from Thermal Decomposition of Formamide

Cataldo, Franco; Patané, Giacomo; Compagnini, Giuseppe

doi:10.1080/10601320903245342

Cited by 45 publications

(33 citation statements)

References 29 publications

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“…In this process, the use of dimethylformimidamides 5 and 6 showed to be an attractive method that allowed a short reaction time (30 min) associated to a convenient temperature of 170°C to avoid the in situ hydrogen cyanide formation, which is traditionally produced by thermal decomposition of formamide at higher temperatures (200–220°C) . Considering these facts, we confirmed that our method constitutes an interesting and safe alternative to the harsh conditions usually described in the literature .…”

Section: Resultssupporting

confidence: 79%

Efficient New Synthesis of N‐Arylbenzo[b]furo[3,2‐d]pyrimidin‐4‐amines and Their Benzo[b]thieno[3,2‐d]pyrimidin‐4‐amine Analogues via a Microwave‐Assisted Dimroth Rearrangement

Loidreau

Dubouilh-Benard

Marchand

et al. 2013

Journal of Heterocyclic Chem

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Section: Resultssupporting

confidence: 79%

Efficient New Synthesis of N‐Arylbenzo[b]furo[3,2‐d]pyrimidin‐4‐amines and Their Benzo[b]thieno[3,2‐d]pyrimidin‐4‐amine Analogues via a Microwave‐Assisted Dimroth Rearrangement

Loidreau

Dubouilh-Benard

Marchand

et al. 2013

Journal of Heterocyclic Chem

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“…6,7,51,52 This was confirmed by theoretical calculations at the CCSD(T)/CBS level, showing that these two decomposition pathways of FM in the lower-lying excited states have much lower energy barriers (DE # : 5-8 kcal mol À1 ) as compared to the dehydration barriers (DE # : 51 kcal mol À1 ). 53 Similar change in the dominant decomposition pathway following the addition of catalysts is also observed in the MO-assisted decompositions of FM. 53 Similar change in the dominant decomposition pathway following the addition of catalysts is also observed in the MO-assisted decompositions of FM.…”

Section: View Article Onlinesupporting

confidence: 53%

Decomposition pathways of formamide in the presence of vanadium and titanium monoxides

Nguyen

2015

Phys. Chem. Chem. Phys.

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Thermally feasible decomposition pathways of formamide (FM) in the presence of vanadium VO(X(4)Σ(-)) and titanium TiO(X(3)Δ) monoxides are determined using density functional theory (BP86 functional) and coupled-cluster theory (CCSD(T)) computations with large basis sets. These diatomic metal oxides have been shown to be present in the prebiotic conditions. The dehydration, decarbonylation and dehydrogenation reactions of the molecular and dissociative complexes of FM and MO (M = V, Ti) turn out to be more favourable than those of the ground state isolated FM. The effect of addition of one or two water molecules on energy barriers is also probed for these reaction pathways. In some cases, a combined catalytic effect when adding water is observed. This enhanced catalytic effect was not observed in previously reported cases of FM transformation, for example, when adding water molecules into the mineral-catalyzed isomerizations of FM. The dehydration process of MO-FM complexes without the presence of water is found to be more feasible than the decarbonylation and dehydrogenation. The overall energy barrier for the non-water VO-FM dehydration is ∼3 kcal mol(-1) lower than the reference energy of the separated systems, whereas those of the two latter reactions are higher than the reference. Although the TiO-FM dehydration has a larger overall barrier of 14 kcal mol(-1) as compared to the VO-FM counterpart, the two other decomposition pathways still have much higher energy barriers. Direct formation of urea and H2CO from a FM dimer and indirect formation of urea from FM via the intermediate HNCO are also established. Urea formation in an indirect pathway is preferred. These low-energy-barrier pathways leading to the formation of important prebiotic molecules suggest that metal monoxides MO could play an important catalytic role in the prebiotic reactions of FM.

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“…Maier and Endres [101] have determined that irradiation of formamide (F) at 248 nm rapidly converts it into basically two tautomeric isomers of formimidic acid (Fa), H(OH)C=NH, which are both about 3.6 kcal mol −1 in energy above formamide and separated from it by a transition barrier of height of E a = 45.4 kcal mol −1 (gas phase). Similarly, Duvernay et al [102] [111]. Our model, therefore, assumes that the F → Fa tautomerization requires the absorption of a photon and we take the wavelength region for tautomerization due to the n → π * transition of 220± 10 nm and assign an average molar extinction coefficient to that region of 60 M −1 cm −1 as measured by Basch et al [90] and also by Petersen et al [89].…”

Section: A Photon-induced Tautomerization Converts Formamide (F) Intomentioning

confidence: 87%

“…x with its most stable tetramer (x = 4) known as cis-DAMN (C) being the preferred polymer from which more complex polymers can be synthesized [111]. The tetramization of 4HCN is an exothermic thermal reaction and occurs most rapidly at a solvent pH at its pKa value, which decreases with increasing temperature (pKa = 8.5 at 60 • C and 7.9 at 100 • C) [68].…”

Section: Hcn (H) Thermally Polymerizes Into (Hcn)mentioning

confidence: 99%

The Dissipative Photochemical Origin of Life: UVC Abiogenesis of Adenine

Michaelian

2021

Entropy

108

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The non-equilibrium thermodynamics and the photochemical reaction mechanisms are described which may have been involved in the dissipative structuring, proliferation and complexation of the fundamental molecules of life from simpler and more common precursors under the UVC photon flux prevalent at the Earth’s surface at the origin of life. Dissipative structuring of the fundamental molecules is evidenced by their strong and broad wavelength absorption bands in the UVC and rapid radiationless deexcitation. Proliferation arises from the auto- and cross-catalytic nature of the intermediate products. Inherent non-linearity gives rise to numerous stationary states permitting the system to evolve, on amplification of a fluctuation, towards concentration profiles providing generally greater photon dissipation through a thermodynamic selection of dissipative efficacy. An example is given of photochemical dissipative abiogenesis of adenine from the precursor HCN in water solvent within a fatty acid vesicle floating on a hot ocean surface and driven far from equilibrium by the incident UVC light. The kinetic equations for the photochemical reactions with diffusion are resolved under different environmental conditions and the results analyzed within the framework of non-linear Classical Irreversible Thermodynamic theory.

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Synthesis of HCN Polymer from Thermal Decomposition of Formamide

Cited by 45 publications

References 29 publications

Efficient New Synthesis of N‐Arylbenzo[b]furo[3,2‐d]pyrimidin‐4‐amines and Their Benzo[b]thieno[3,2‐d]pyrimidin‐4‐amine Analogues via a Microwave‐Assisted Dimroth Rearrangement

Efficient New Synthesis of N‐Arylbenzo[b]furo[3,2‐d]pyrimidin‐4‐amines and Their Benzo[b]thieno[3,2‐d]pyrimidin‐4‐amine Analogues via a Microwave‐Assisted Dimroth Rearrangement

Decomposition pathways of formamide in the presence of vanadium and titanium monoxides

The Dissipative Photochemical Origin of Life: UVC Abiogenesis of Adenine

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