{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.carbon-hydrogen-bond-activation","code":"thing-q900254","url":"https://ver.cy/models/thing/q900254/","name":"carbon–hydrogen bond activation","alternateNames":[],"kind":"thing","status":"published","version":"0.1.0-research.1","language":"en","classifiers":{"family":"Thing Registry","category":"Activities and processes","entryKind":"thing","plane":"ACT","domain":["ACT.PRC"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"Carbon-hydrogen bond activation is the cleavage of a C-H bond through interaction with a reactive species, classically a transition-metal centre, to produce intermediates that can undergo further reaction, although usage varies over whether radical and other nonmetal-mediated pathways are included.","purpose":"Enable an agent to recognise a claimed carbon-hydrogen bond activation event, assess its mechanistic evidence and select justified next investigations or synthetic uses.","scope":{"in":["Operational definitions of C-H activation and their attribution to particular sources or research communities","Identification of the substrate C-H site and the fate of its carbon and hydrogen atoms","Activating species, reaction environment and proposed elementary mechanism","Site discrimination, reversibility and the relationship between activation and productive conversion","Experimental and computational evidence supporting or challenging activation assignments"],"out":["Complete synthesis routes and downstream product applications","Standalone models of substrates, catalysts, ligands and solvents","General C-H functionalization pathways except where needed to locate the activation event","General chemical activation terminology unrelated to a particular C-H bond","Laboratory equipment operation and full process safety assessments"],"boundaries":[]},"distinguishingFeatures":["An instance must identify an initially present C-H bond and evidence or a testable proposal for what happens to that bond.","Record the adopted definition: a metal-mediated bond-cleavage usage and a broader usage encompassing other cleavage pathways must not be silently treated as equivalent. Terminological inconsistency is discussed in [The continuum of carbon-hydrogen activation mechanisms and terminology](https://www.nature.com/articles/s42004-021-00611-1).","Distinguish the activation event from the overall functionalization outcome; a catalytic account can assign these to separate steps. See [C-H Activation: Toward Sustainability and Applications](https://pubs.acs.org/doi/10.1021/acscentsci.0c01413).","Distinguish coordination or bond weakening from demonstrated cleavage, and distinguish evidence for cleavage from evidence for a particular mechanism.","A transformation starting from a carbon-halogen or preformed carbon-metal bond does not establish activation of a C-H bond at that carbon."],"structure":{"bundles":[{"id":"activation-identity-and-boundaries","name":"Activation identity and boundaries","description":"Establish what the claim calls activation and which bond-level event it concerns.","layers":[{"id":"terminological-commitment","name":"Terminological commitment","description":"Make the inclusion rule and its provenance explicit.","findings":[{"id":"adopted-activation-definition","name":"Adopted activation definition","description":"Record the source's definition separately from the model's operational classification.","questions":[{"text":"What does the reporting source require for an event to count as C-H activation?","id":"adopted-activation-definition-q01","kind":"definition"},{"text":"Under that definition, are hydrogen-atom transfer, ordinary deprotonation and metal-free cleavage included or excluded?","id":"adopted-activation-definition-q02","kind":"boundary"}]}]},{"id":"bond-event-identification","name":"Bond event identification","description":"Locate the particular C-H bond and separate its event from the net reaction.","findings":[{"id":"mapped-bond-and-event","name":"Mapped bond and event","description":"Require an identifiable starting bond and distinguish observed atom changes from inferred elementary steps.","questions":[{"text":"Which substrate carbon and hydrogen define the claimed activation site?","id":"mapped-bond-and-event-q01","kind":"definition"},{"text":"What establishes cleavage rather than coordination, bond weakening or inference from the final product alone?","id":"mapped-bond-and-event-q02","kind":"provenance"}]}]}]},{"id":"substrate-sites-and-selection","name":"Substrate sites and selection","description":"Represent the local C-H environments and the basis for distinguishing competing sites.","layers":[{"id":"candidate-site-map","name":"Candidate site map","description":"Describe the target and chemically competing C-H positions.","findings":[{"id":"local-environment-and-competitors","name":"Local environment and competitors","description":"Record hybridization, substitution, nearby groups and the number of equivalent hydrogens at each candidate site.","questions":[{"text":"What structural features distinguish the target C-H site from the other available sites?","id":"local-environment-and-competitors-q01","kind":"definition"},{"text":"Are reported site ratios corrected for the number of equivalent C-H bonds, and how were sites assigned?","id":"local-environment-and-competitors-q02","kind":"measurement"}]}]},{"id":"selectivity-origin","name":"Selectivity origin","description":"Separate proposed directing effects from measured activation and product distributions.","findings":[{"id":"site-control-evidence","name":"Site control evidence","description":"Record proposed coordination, steric or electronic control as hypotheses tied to comparisons.","questions":[{"text":"Which experiments test whether a directing group or other substrate feature controls C-H cleavage?","id":"site-control-evidence-q01","kind":"provenance"},{"text":"Does the measured selectivity describe cleavage, an intermediate population or the final products?","id":"site-control-evidence-q02","kind":"boundary"}]}]}]},{"id":"cleavage-system-and-mechanism","name":"Cleavage system and mechanism","description":"Specify the species and bond changes proposed to accomplish C-H activation.","layers":[{"id":"active-species-and-environment","name":"Active species and environment","description":"Connect the activation claim to the species and conditions actually present.","findings":[{"id":"activation-competent-system","name":"Activation-competent system","description":"Distinguish charged reagents or precatalysts from assigned active species, including unresolved speciation.","questions":[{"text":"Which molecular species or surface site is proposed to activate the bond, and what supports its presence?","id":"activation-competent-system-q01","kind":"provenance"},{"text":"What temperature, medium, additives, atmosphere and energy input bound the observation?","id":"activation-competent-system-q02","kind":"measurement"}]}]},{"id":"elementary-bond-changes","name":"Elementary bond changes","description":"Describe the proposed cleavage without forcing uncertain assignments into a single mechanism label.","findings":[{"id":"mechanism-and-hydrogen-destination","name":"Mechanism and hydrogen destination","description":"Record bond breaking, bond formation, charge or oxidation-state changes and alternative assignments.","questions":[{"text":"Where does the hydrogen go, what happens at carbon, and which of these changes have been observed?","id":"mechanism-and-hydrogen-destination-q01","kind":"provenance"},{"text":"Which bond-change evidence distinguishes the proposed mechanism from the strongest alternative?","id":"mechanism-and-hydrogen-destination-q02","kind":"boundary"}]}]}]},{"id":"mechanistic-evidence-and-kinetics","name":"Mechanistic evidence and kinetics","description":"Make activation assignments auditable through their measurements and competing interpretations.","layers":[{"id":"observation-and-assignment","name":"Observation and assignment","description":"Separate measured signals from structural and mechanistic interpretations.","findings":[{"id":"traceable-activation-evidence","name":"Traceable activation evidence","description":"Connect spectra, isotope tracing, trapped species and computations to specific claims and limitations.","questions":[{"text":"Which accessible report or dataset supports each claimed intermediate, atom assignment or computed pathway?","id":"traceable-activation-evidence-q01","kind":"provenance"},{"text":"What control would distinguish the assigned species from an off-cycle species or alternative structure?","id":"traceable-activation-evidence-q02","kind":"action"}]}]},{"id":"rate-and-reversibility","name":"Rate and reversibility","description":"Determine what kinetic measurements establish about cleavage and its role in the reaction.","findings":[{"id":"kinetic-interpretation","name":"Kinetic interpretation","description":"Record rate laws, isotope effects and exchange observations with their experimental design and alternative explanations.","questions":[{"text":"How were rates and isotope effects measured, and what uncertainty and concentration dependence were reported?","id":"kinetic-interpretation-q01","kind":"measurement"},{"text":"What evidence distinguishes reversible cleavage, rate-influencing cleavage and a later rate-controlling step?","id":"kinetic-interpretation-q02","kind":"boundary"}]}]}]},{"id":"productive-coupling-and-transfer","name":"Productive coupling and transfer","description":"Relate activation to useful reaction outcomes and assess where the evidence supports reuse.","layers":[{"id":"activation-to-product-link","name":"Activation-to-product link","description":"Track whether the activated species enters the proposed productive pathway.","findings":[{"id":"productive-participation","name":"Productive participation","description":"Distinguish stoichiometric activation, exchange, catalyst trapping and productive turnover.","questions":[{"text":"What evidence connects the activated intermediate to product formation under the reported reaction conditions?","id":"productive-participation-q01","kind":"provenance"},{"text":"Does the experiment establish only an activation event, or also catalyst regeneration and repeated turnover?","id":"productive-participation-q02","kind":"boundary"}]}]},{"id":"scope-limits-and-next-tests","name":"Scope limits and next tests","description":"Turn reported successes, failures and unresolved assignments into bounded next actions.","findings":[{"id":"evidence-bounded-reuse","name":"Evidence-bounded reuse","description":"Record substrate and condition differences that require validation before transferring an activation claim.","questions":[{"text":"Which failed substrates or changed conditions delimit the reported activation, and what failure evidence was collected?","id":"evidence-bounded-reuse-q01","kind":"provenance"},{"text":"What smallest discriminating experiment would test activation at the intended site in the proposed new substrate?","id":"evidence-bounded-reuse-q02","kind":"action"}]}]}]},{"id":"evidence-and-external-alignment","name":"Evidence and external alignment","description":"What the world already says about this thing, gathered so the model can be checked against it.","layers":[{"id":"reported-evidence","name":"Reported evidence","description":"Findings from the breadth pass, kept separate from the structural claims.","findings":[{"id":"evidence-confidence-notes","name":"Check these first","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these check these first hold for the sense of carbon-hydrogen bond activation this model covers, and on what evidence?","id":"evidence-confidence-notes-q01","kind":"provenance"}]},{"id":"evidence-kinds","name":"Kinds and varieties","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these kinds and varieties hold for the sense of carbon-hydrogen bond activation this model covers, and on what evidence?","id":"evidence-kinds-q01","kind":"provenance"}]},{"id":"evidence-real-world-use","name":"Real-world use","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these real-world use hold for the sense of carbon-hydrogen bond activation this model covers, and on what evidence?","id":"evidence-real-world-use-q01","kind":"provenance"}]},{"id":"evidence-measurements","name":"Typical measurements","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these typical measurements hold for the sense of carbon-hydrogen bond activation this model covers, and on what evidence?","id":"evidence-measurements-q01","kind":"provenance"}]},{"id":"evidence-failure-modes-and-hazards","name":"Failure modes and hazards","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these failure modes and hazards hold for the sense of carbon-hydrogen bond activation this model covers, and on what evidence?","id":"evidence-failure-modes-and-hazards-q01","kind":"provenance"}]},{"id":"evidence-neighbours","name":"Neighbouring kinds and how to tell them apart","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these neighbouring kinds and how to tell them apart hold for the sense of carbon-hydrogen bond activation this model covers, and on what evidence?","id":"evidence-neighbours-q01","kind":"provenance"}]}]}]}]},"agentConduct":{"may":["Explain C-H activation concepts and their uses in synthesis from published sources.","Summarize literature for researchers working in authorized laboratories."],"mustNot":["Help make harmful or controlled substances using these methods.","Misreport yields, selectivity or results from studies.","Advise running reactions with toxic metals or reagents outside a properly equipped laboratory."],"requiresHuman":["Scaling a reaction up from laboratory to production."]},"ethics":{"considerations":["Cleaner synthesis can reduce waste, but metal catalysts can be toxic and scarce.","Research integrity matters because others build on reported results."],"affectedParties":["Laboratory workers","Researchers","Communities near chemical plants"]},"owners":{"steward":"Nobody owns the concept; laboratories answer for their own work.","roles":[],"masterSystems":[]},"relations":[{"target":"Q36534","type":"parent","note":"registry parent class"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.carbon-hydrogen-bond-activation","Wikidata: Q900254 (https://www.wikidata.org/wiki/Q900254)"]},"properties":{"applicability":"not-applicable","items":["Definition adopted: Source-attributed definition; narrow metal-mediated usage, broader cleavage usage, disputed or unspecified","Target C-H site: Substrate identifier plus atom-mapped carbon and hydrogen or explicitly defined equivalent sites","C-H environment: Carbon hybridization; aromatic, benzylic, allylic, aliphatic or other environment; nearby functional groups","Activating species: Assigned molecular species or surface site; composition, charge and oxidation state where meaningful; assignment confidence","Mechanistic assignment: Oxidative addition, concerted metalation-deprotonation, sigma-bond metathesis, other explicitly described pathway, competing assignments or unknown","Activation conditions: Temperature in K; pressure in bar; concentration in mol/L; reaction time in s; light or electrode parameters when relevant","Activation reversibility: Observed reversible, consistent with reversible, effectively irreversible under stated conditions or unresolved","Site selectivity: Site-resolved rate ratio or intermediate/product ratio, with sampling time and analytical method","Kinetic isotope effect: Dimensionless kH/kD with experimental design, conditions and uncertainty","Evidence status: Proposed, indirectly supported, directly observed intermediate or event, contested or unresolved"]},"recognition":{"applicability":"not-applicable","items":[]},"capabilities":{"applicability":"required","items":["Classify a reported transformation against an explicit definition of C-H activation.","Map candidate C-H sites and identify evidence needed to distinguish their activation.","Compare competing cleavage mechanisms against observed atom fate, kinetics and intermediates.","Separate demonstrated activation from productive turnover and downstream selectivity.","Propose discriminating isotope, kinetic or spectroscopic investigations.","Assess whether a reported activation is relevant to a new substrate while recording limits of transfer."]},"hazards":{"applicability":"required","items":["Reagents and metal catalysts can be toxic, flammable or reactive.","Residual metals can contaminate products."]},"interfaces":{"applicability":"not-applicable","items":[]},"context":{"applicability":"required","items":["Carbon-hydrogen bond activation is studied in organometallic chemistry, catalysis and synthetic chemistry.","It can enable the subsequent conversion of a carbon-hydrogen bond into another bond when incorporated into a suitable reaction pathway.","Researchers use mechanistic evidence to distinguish an activation step from the overall functionalisation outcome."]}},"sources":[{"title":"Wikidata item Q900254: carbon–hydrogen bond activation","url":"https://www.wikidata.org/wiki/Q900254","note":"identity and sense of the item"},{"title":"Wikipedia: Carbon–hydrogen bond activation","url":"https://en.wikipedia.org/wiki/Carbon%E2%80%93hydrogen_bond_activation","note":"general description of the item"}],"openQuestions":["Which source-attributed definition should anchor this registry entry, and how should broader uses involving hydrogen-atom transfer or deprotonation be related to it?","Does an existing Vercy world model already cover this concept, requiring a registry link instead of a separate publication?","What evidence threshold should distinguish established C-H activation from a plausible step inferred from functionalization products?","How should the model represent mechanisms that occupy a continuum or remain experimentally indistinguishable?","Which additional descriptors are necessary for heterogeneous or enzyme-mediated activation while preserving a common bond-event model?"],"resources":{"spec":"/models/things/publications/thing-q900254/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q900254/spec.json"],"providers":["Codex"],"researchStatus":"unreviewed","generatedAt":"2026-09-12T08:22:55Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"filled","ethics":"filled","owners":"filled","relations":"filled","interaction.identity":"filled","interaction.properties":"not-applicable","interaction.recognition":"not-applicable","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"not-applicable","interaction.context":"filled","sources":"filled"},"notes":{"_gate":"Published through the thing publication gate 1.0 on 2026-10-07T10:10:33+00:00: completeness 1.00; sense: Wikidata description; 2 live sources; review by codex: pass","interaction.properties":"Plane ACT: no invented physical properties.","interaction.interfaces":"No universal standard or regulation applies specifically to this reaction class, while requirements for particular chemicals and laboratory activities depend on the setting.","interaction.recognition":"A carbon-hydrogen bond activation event cannot be identified visually and requires chemical analysis and mechanistic evidence."},"score":1.0}}