{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"submitter":["Elter M"],"funding":["Klaus Tschira Stiftung","Deutsche Forschungsgemeinschaft"],"pagination":["27594-27599"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC11468784"],"repository":["biostudies-literature"],"omics_type":["Unknown"],"volume":["146(40)"],"pubmed_abstract":["Stronger chemical bonds withstand higher mechanical forces; thus, the rupture of single bonds is preferred over the rupture of double or triple bonds or aromatic rings. We investigated bond scission in poly(dialkyl-<i>p</i>-phenylene ethynylene)s (PPEs), a fully conjugated polymer. In a scale-bridging approach using electron-paramagnetic resonance spectroscopy and gel permeation chromatography of cryomilled samples, in combination with density functional theory calculations and coarse-grained simulations, we conclude that mechanical force cleaves the sp-sp<sup>2</sup> bond of PPEs (bond dissociation energy as high as 600 kJ mol<sup>-1</sup>). Bond scission primarily occurs in shear bands with locally increased shear stresses. The scission occurs in the middle of the PPE chains. Breaking sp-sp<sup>2</sup> bonds into free radicals thus is feasible but requires significant mechanical force and an efficient stress concentration."],"journal":["Journal of the American Chemical Society"],"pubmed_title":["Breaking Strong Alkynyl-Phenyl Bonds: Poly(&lt;i&gt;para&lt;/i&gt;-phenylene ethynylene)s under Mechanical Stress."],"pmcid":["PMC11468784"],"funding_grant_id":["EXC-2082 - 1-390761711"],"pubmed_authors":["Bunz UHF","Grater F","Brosz M","Kiesewetter DC","Freudenberg J","Elter M","Kuzhelev A","Dreuw A","Sucerquia D","Kurth M","Prisner TF"],"additional_accession":[]},"is_claimable":false,"name":"Breaking Strong Alkynyl-Phenyl Bonds: Poly(&lt;i&gt;para&lt;/i&gt;-phenylene ethynylene)s under Mechanical Stress.","description":"Stronger chemical bonds withstand higher mechanical forces; thus, the rupture of single bonds is preferred over the rupture of double or triple bonds or aromatic rings. We investigated bond scission in poly(dialkyl-<i>p</i>-phenylene ethynylene)s (PPEs), a fully conjugated polymer. In a scale-bridging approach using electron-paramagnetic resonance spectroscopy and gel permeation chromatography of cryomilled samples, in combination with density functional theory calculations and coarse-grained simulations, we conclude that mechanical force cleaves the sp-sp<sup>2</sup> bond of PPEs (bond dissociation energy as high as 600 kJ mol<sup>-1</sup>). Bond scission primarily occurs in shear bands with locally increased shear stresses. The scission occurs in the middle of the PPE chains. Breaking sp-sp<sup>2</sup> bonds into free radicals thus is feasible but requires significant mechanical force and an efficient stress concentration.","dates":{"release":"2024-01-01T00:00:00Z","publication":"2024 Oct","modification":"2025-04-18T13:20:41.377Z","creation":"2025-04-06T22:57:40.455Z"},"accession":"S-EPMC11468784","cross_references":{"pubmed":["39332820"],"doi":["10.1021/jacs.4c08765"]}}