title: Formation of Hexamethylenetetramine (HMT) from HCHO and NH3--Relevance to Prebiotic Chemistry and B3LYP Consideration.
abstract: Despite its importance in the prebiotic and biochemical fields, a complete theoretical study of the formation of hexamethylenetetramine (HMT) starting from its precursors ammonia and formaldehyde has not received due considerations in the literature with regard to the thermodynamic feasibility of many of the mechanistically proposed intermediates in its formation. Most of the studies in this area have been mostly concerned with the initial steps of the reaction between formaldehyde and ammonia, while poor attention is dedicated to successive steps. In this article, different results from published literature were critically considered and the most probable hypothesis regarding the mechanism of HMT formation is discussed on the basis of B3LYP calculations of free energies.
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Pavia, V.le Taramelli 12, Pavia, 27100, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Zeffiro
authors.affiliation: Istituto Nazionale di Ricerca Metrologica (INRIM), Unità di Radiochimica e Spettroscopia, c/o Dipartimento di Chimica, Università degli Studi di Pavia, V.le Taramelli 12, 27100, Pavia, Italy. s.lazzaroni@inrim.it.
authors.forename: Simone
authors.initials: S
authors.lastname: Lazzaroni
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Pavia, V.le Taramelli 12, Pavia, 27100, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Merli
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Pavia, V.le Taramelli 12, Pavia, 27100, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Profumo
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Pavia, V.le Taramelli 12, Pavia, 27100, Italy.
authors.forename: Armando
authors.initials: A
authors.lastname: Buttafava
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Pavia, V.le Taramelli 10, Pavia, 27100, Italy.
authors.forename: Nick
authors.initials: N
authors.lastname: Serpone
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Pavia, V.le Taramelli 12, Pavia, 27100, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Dondi
mesh_terms: D000641:Ammonia / Q000737:chemistry*; D019418:Evolution, Chemical; D005557:Formaldehyde / Q000737:chemistry*; D008709:Methenamine / Q000138:chemical synthesis*; D008956:Models, Chemical; D000069497:Origin of Life; D011789:Quantum Theory; D013816:Thermodynamics
chemical_list: D005557:Formaldehyde; D000641:Ammonia; D008709:Methenamine
keywords: B3LYP; HMT; Prebiotic chemistry; Reaction mechanism