{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.cyclopentadienylthallium","code":"thing-q5198931","url":"https://ver.cy/models/thing/q5198931/","name":"cyclopentadienylthallium","alternateNames":[],"kind":"thing","status":"published","version":"0.1.0-research.1","language":"en","classifiers":{"family":"Thing Registry","category":"Physical world and living systems","entryKind":"thing","plane":"PHY","domain":["PHY.MAT"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"Cyclopentadienylthallium is an organothallium(I) compound of formula C5H5Tl, conventionally written CpTl, containing the cyclopentadienyl anion and thallium in the +1 oxidation state.","purpose":"Enable an agent to recognise cyclopentadienylthallium, assess a sample's identity and condition, and determine whether a proposed use has adequate chemical and handling evidence.","scope":{"in":["Unsubstituted cyclopentadienylthallium identity and identifier equivalence","Cyclopentadienyl-to-thallium stoichiometry and phase-specific coordination","Sample assay, impurities, residual solvents and deterioration","Physical properties with measurement conditions and uncertainty","Evidence for reagent suitability and thallium-specific handling constraints"],"out":["Substituted cyclopentadienylthallium compounds, including pentamethyl derivatives","Cyclopentadiene, dicyclopentadiene and other metal cyclopentadienides as independent substances","Commercial product packaging, pricing and supplier operations","Detailed synthesis procedures and reaction-process operation","Downstream complexes and their independent material properties","Clinical management of thallium exposure"],"boundaries":[]},"distinguishingFeatures":["Match C5H5Tl and CAS 34822-90-7; NIST also lists thallium(I) cyclopentadienide as a synonym. [NIST Chemistry WebBook](https://webbook.nist.gov/cgi/cbook.cgi?ID=34822-90-7)","Require an unsubstituted C5H5 cyclopentadienyl group; methylated or otherwise substituted rings define neighbouring substances.","Require thallium as the associated metal; sodium, lithium and other metal cyclopentadienides do not satisfy this identity.","Distinguish the cyclopentadienyl compound from free cyclopentadiene or an inorganic thallium salt using structural evidence, rather than total thallium alone.","Treat C5H5Tl as compositional identity without assuming that a single molecular drawing establishes aggregation or coordination in every phase."],"structure":{"bundles":[{"id":"chemical-identity","name":"Chemical identity","description":"Establish the exact parent compound and its registry boundary.","layers":[{"id":"names-and-identifiers","name":"Names and identifiers","description":"Resolve names and external records to the registered substance.","findings":[{"id":"identifier-equivalence","name":"Identifier equivalence","description":"Record which identifiers denote unsubstituted cyclopentadienylthallium and retain evidence for each mapping.","questions":[{"text":"Which authoritative records connect the registry entry to CAS 34822-90-7, a PubChem CID and any verified EC number?","id":"identifier-equivalence-q01","kind":"provenance"},{"text":"Does the supplied name identify the parent compound, a substituted derivative or a formulated product?","id":"identifier-equivalence-q02","kind":"boundary"}]}]},{"id":"composition-and-ligand-boundary","name":"Composition and ligand boundary","description":"Define the cyclopentadienyl group and thallium association required for recognition.","findings":[{"id":"parent-compound-test","name":"Parent compound test","description":"Require evidence of the unsubstituted cyclopentadienyl compound rather than accepting elemental composition alone.","questions":[{"text":"What compositional and structural evidence establishes the C5H5 ligand and nominal 1:1 association with thallium?","id":"parent-compound-test-q01","kind":"definition"},{"text":"Which observations exclude free cyclopentadiene, inorganic thallium salts and substituted cyclopentadienyl compounds?","id":"parent-compound-test-q02","kind":"measurement"}]}]}]},{"id":"coordination-and-phase","name":"Coordination and phase","description":"Represent bonding and physical behaviour under explicitly recorded conditions.","layers":[{"id":"phase-specific-structure","name":"Phase-specific structure","description":"Attach coordination and aggregation assignments to the phase actually examined.","findings":[{"id":"coordination-evidence","name":"Coordination evidence","description":"Separate measured hapticity and aggregation from conventional structural representations.","questions":[{"text":"Which diffraction or spectroscopic evidence supports the proposed thallium-ring coordination and aggregation?","id":"coordination-evidence-q01","kind":"provenance"},{"text":"Does that evidence describe a crystal, solution or vapour, and under which conditions?","id":"coordination-evidence-q02","kind":"boundary"}]}]},{"id":"physical-property-envelope","name":"Physical property envelope","description":"Capture thermal and solvent behaviour without conflating phase change with chemical change.","findings":[{"id":"condition-qualified-properties","name":"Condition-qualified properties","description":"Record measured constants together with evidence that the compound retains its identity during measurement.","questions":[{"text":"Which reported thermal events are melting, sublimation or decomposition, and what pressure and atmosphere were used?","id":"condition-qualified-properties-q01","kind":"measurement"},{"text":"What solubility is measured in each relevant solvent, and how is chemical persistence after dissolution established?","id":"condition-qualified-properties-q02","kind":"measurement"}]}]}]},{"id":"sample-quality-and-stability","name":"Sample quality and stability","description":"Determine how much usable cyclopentadienylthallium a particular sample contains.","layers":[{"id":"assay-and-contaminants","name":"Assay and contaminants","description":"Distinguish the intended compound from residual or transformed material.","findings":[{"id":"usable-compound-content","name":"Usable compound content","description":"Record an assay that separates parent-compound content from total thallium and documents relevant impurities.","questions":[{"text":"Which validated assay distinguishes cyclopentadienylthallium from other thallium-containing species?","id":"usable-compound-content-q01","kind":"measurement"},{"text":"What limits apply to residual solvents, water, organic starting materials and inorganic thallium impurities for the intended use?","id":"usable-compound-content-q02","kind":"action"}]}]},{"id":"storage-and-change","name":"Storage and change","description":"Relate exposure history to evidence of retained identity and performance.","findings":[{"id":"retest-triggers","name":"Retest triggers","description":"Define evidence-based triggers for recharacterisation rather than assuming a shelf life or interpreting colour alone.","questions":[{"text":"What measured changes follow exposure to air, moisture, light or elevated temperature over stated durations?","id":"retest-triggers-q01","kind":"measurement"},{"text":"Which exposure events or analytical changes require retesting or rejection before use?","id":"retest-triggers-q02","kind":"action"}]}]}]},{"id":"reagent-suitability","name":"Reagent suitability","description":"Assess evidence for using this compound as a source of the unsubstituted cyclopentadienyl group.","layers":[{"id":"transfer-role-and-evidence","name":"Transfer role and evidence","description":"Connect proposed ligand-transfer applications to documented outcomes.","findings":[{"id":"supported-transformation","name":"Supported transformation","description":"Record the intended recipient, demonstrated outcome and evidence limits without embedding a synthesis procedure.","questions":[{"text":"Which primary reports demonstrate cyclopentadienyl transfer from this compound to the proposed recipient?","id":"supported-transformation-q01","kind":"provenance"},{"text":"What evidence supports choosing it over another metal cyclopentadienide for that specific transformation?","id":"supported-transformation-q02","kind":"action"}]}]},{"id":"compatibility-and-residues","name":"Compatibility and residues","description":"Assess how sample quality and thallium-bearing residues affect a proposed application.","findings":[{"id":"application-acceptance","name":"Application acceptance","description":"Link reagent acceptance to actual assay, documented compatibility and downstream thallium criteria.","questions":[{"text":"What documented solvent, reagent or impurity incompatibilities constrain the proposed application?","id":"application-acceptance-q01","kind":"boundary"},{"text":"Which assay correction and residual-thallium acceptance criteria must be satisfied before accepting the reagent and its downstream product?","id":"application-acceptance-q02","kind":"action"}]}]}]},{"id":"thallium-hazards-and-disposition","name":"Thallium hazards and disposition","description":"Connect compound-specific hazard evidence and applicable thallium rules to handling and waste decisions.","layers":[{"id":"hazard-and-exposure-basis","name":"Hazard and exposure basis","description":"Distinguish compound-specific classifications from rules covering groups of thallium substances.","findings":[{"id":"applicable-hazard-record","name":"Applicable hazard record","description":"Retain the source, revision and applicability of each classification or exposure limit.","questions":[{"text":"Which current SDS or authoritative classification applies to this exact compound and supplied composition?","id":"applicable-hazard-record-q01","kind":"provenance"},{"text":"Does each applicable exposure limit refer to cyclopentadienylthallium, thallium compounds generally or mass expressed as elemental Tl?","id":"applicable-hazard-record-q02","kind":"boundary"}]}]},{"id":"handling-and-waste-decisions","name":"Handling and waste decisions","description":"Translate verified requirements into constraints on material use and disposition.","findings":[{"id":"controlled-material-disposition","name":"Controlled material disposition","description":"Associate sample form and thallium-bearing residue streams with approved handling and disposal requirements.","questions":[{"text":"What documented containment and handling requirements apply to the actual solid or solution form and proposed operation?","id":"controlled-material-disposition-q01","kind":"action"},{"text":"Which local requirements govern collection and disposal of unused compound, reaction residues and contaminated materials containing thallium?","id":"controlled-material-disposition-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 cyclopentadienylthallium this model covers, and on what evidence?","id":"evidence-confidence-notes-q01","kind":"provenance"}]},{"id":"evidence-identifiers","name":"Identifiers and schemes","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these identifiers and schemes hold for the sense of cyclopentadienylthallium this model covers, and on what evidence?","id":"evidence-identifiers-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 cyclopentadienylthallium 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 cyclopentadienylthallium 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 cyclopentadienylthallium 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 cyclopentadienylthallium this model covers, and on what evidence?","id":"evidence-neighbours-q01","kind":"provenance"}]}]}]}]},"agentConduct":{"may":["Describe its structure and its use as a reagent for transferring cyclopentadienyl groups.","Report the extreme toxicity of thallium compounds from safety data."],"mustNot":["Help anyone obtain, divert or use it, or any thallium compound, to poison a person or animal.","Handle it without containment and protective equipment.","Dispose of thallium waste into drains or general rubbish.","Recommend it where less toxic reagents would do."],"requiresHuman":["Approving purchase, use or disposal of thallium reagents."]},"ethics":{"considerations":["Thallium compounds have been used as poisons; access must be controlled to protect people."],"affectedParties":["Laboratory staff","Potential poisoning victims","Waste handlers"]},"owners":{"steward":"The laboratory that holds it; the supplier answers for its labelling and controlled supply.","roles":[],"masterSystems":[]},"relations":[{"target":"Q11173","type":"parent","note":"registry parent class"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.cyclopentadienylthallium","Wikidata: Q5198931 (https://www.wikidata.org/wiki/Q5198931)"]},"properties":{"applicability":"required","items":["Substance identifier correspondence: Registry id, CAS number, PubChem CID, EC number where verified, source and verification date","Cyclopentadienyl-to-thallium ratio: mol/mol; nominal parent composition 1:1","Thallium oxidation-state assignment: Formal Tl(I) assignment; supporting evidence; unresolved or mixed-species observations","Coordination and aggregation: Ring hapticity, coordination environment and aggregation, with phase and method","Compound-specific assay: Mass % or mol %, analytical method, uncertainty and reporting basis","Impurity profile: Mass %, ppm or detection limit for identified thallium species, organic residues, water and solvents","Thermal behaviour: Melting, decomposition or sublimation observations in °C or K, with pressure, atmosphere and method","Solubility and solution persistence: g/L or mol/L by solvent and temperature; observation duration and species evidence","Exposure and storage history: Temperature, atmosphere, humidity, light exposure, elapsed time and observed changes","Applicable hazard and regulatory record: Current SDS, jurisdiction, GHS statements, exposure-limit basis and waste requirements"]},"recognition":{"applicability":"required","items":["A pale yellow solid, often stored under inert gas and away from light."]},"capabilities":{"applicability":"required","items":["Resolve a label or database record to the unsubstituted cyclopentadienylthallium identity.","Compare analytical results against compound-specific identity and purity criteria.","Calculate nominal reagent quantity from sample mass and a verified assay basis.","Assess a proposed cyclopentadienyl-transfer application against documented compatibility evidence.","Flag samples requiring recharacterisation after storage or exposure changes.","Associate handling and disposal decisions with applicable thallium-containing material requirements."]},"hazards":{"applicability":"required","items":["Thallium is highly toxic by swallowing, inhalation and skin contact.","Poisoning can be delayed and cause hair loss and nerve damage."]},"interfaces":{"applicability":"required","items":["Globally Harmonized System of Classification and Labelling of Chemicals (GHS), United Nations."]},"context":{"applicability":"required","items":["Cyclopentadienylthallium is encountered in specialist organometallic chemistry research as a reagent for introducing cyclopentadienyl groups into other compounds.","It is also studied to understand the bonding and structures of thallium-containing organometallic materials."]}},"sources":[{"title":"Wikidata item Q5198931: cyclopentadienylthallium","url":"https://www.wikidata.org/wiki/Q5198931","note":"identity and sense of the item"},{"title":"Wikipedia: Cyclopentadienylthallium","url":"https://en.wikipedia.org/wiki/Cyclopentadienylthallium","note":"general description of the item"}],"openQuestions":["Which primary structural studies establish coordination and aggregation in the solid, solution and vapour phases, and where do their conclusions differ?","What reliable melting, decomposition, sublimation, solubility and possible boiling data exist with explicit conditions and sample purity?","Which compound-specific assay and impurity limits best predict suitability for documented cyclopentadienyl-transfer applications?","What measured evidence establishes sensitivity to air, moisture and light, acceptable storage conditions and retest intervals?","Which PubChem and EC mappings, current GHS classifications and jurisdiction-specific exposure and waste requirements are verified for this exact substance?"],"resources":{"spec":"/models/things/publications/thing-q5198931/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q5198931/spec.json"],"providers":["Codex"],"researchStatus":"unreviewed","generatedAt":"2026-09-12T08:58:27Z","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":"filled","interaction.recognition":"filled","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"filled","interaction.context":"filled","sources":"filled"},"notes":{"_gate":"Published through the thing publication gate 1.0 on 2026-10-07T10:10:31+00:00: completeness 1.00; sense: Wikidata description; 2 live sources; review by codex: pass"},"score":1.0}}