{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.cyclen","code":"thing-q416407","url":"https://ver.cy/models/thing/q416407/","name":"cyclen","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":"Cyclen is 1,4,7,10-tetraazacyclododecane, a saturated twelve-membered macrocyclic amine with formula C8H20N4 whose four nitrogen atoms can coordinate metal ions.","purpose":"Enable an agent to identify cyclen, assess the chemical form and quality of a sample, and determine its suitability for coordination or derivatization work.","scope":{"in":["Identity and connectivity of unsubstituted cyclen","Free-base content, purity, water, and residual contaminants","Physical state and condition-dependent material properties","Protonation and availability of nitrogen donor sites","Suitability for metal coordination and nitrogen functionalization","Form-specific handling requirements and regulatory identifiers"],"out":["Independent substance identities of cyclen salts and hydrates","Covalently substituted derivatives such as DOTA","Metal-cyclen complexes as independently characterized substances","Manufacturing routes and reaction procedures","Commercial formulations containing cyclen","Clinical performance of downstream contrast agents or radiopharmaceuticals"],"boundaries":[]},"distinguishingFeatures":["Cyclen has a saturated 12-membered ring with nitrogen at positions 1, 4, 7, and 10; its neutral parent formula is C8H20N4. [PubChem](https://pubchem.ncbi.nlm.nih.gov/compound/1_4_7_10-Tetraazacyclododecane)","Identity matching should resolve to CAS 294-90-6 and PubChem CID 64963, supported by structural evidence rather than name similarity. [Fisher Scientific](https://www.fishersci.com/us/en/browse/cas/294-90-6)","All four parent nitrogen sites are secondary amines without pendant substituents; covalent substitution must trigger a derivative boundary rather than a purity-grade change.","A tetrahydrochloride label denotes a separate salt form with formula C8H24Cl4N4, not the neutral parent's formula or mass basis. [PubChem](https://pubchem.ncbi.nlm.nih.gov/compound/Cyclen-tetrahydrochloride)","A trihydrate must be distinguished from anhydrous parent material when assigning formula and calculating cyclen content. [PubChem](https://pubchem.ncbi.nlm.nih.gov/compound/71345808)"],"structure":{"bundles":[{"id":"macrocycle-identity","name":"Macrocycle identity","description":"Establish the parent ring and separate it from related chemical entities.","layers":[{"id":"ring-connectivity","name":"Ring connectivity","description":"Verify the defining nitrogen arrangement and unsubstituted parent structure.","findings":[{"id":"parent-structure-evidence","name":"Parent structure evidence","description":"Recognition requires evidence consistent with the 12-membered tetraamine ring.","questions":[{"text":"Does the assigned structure contain four NH sites at positions 1, 4, 7, and 10 with ethylene spacers?","id":"parent-structure-evidence-q01","kind":"definition"},{"text":"Which analytical evidence distinguishes the sample from ring-size analogues or substituted cyclen?","id":"parent-structure-evidence-q02","kind":"measurement"}]}]},{"id":"chemical-entity-boundaries","name":"Chemical entity boundaries","description":"Separate the parent reference identity from the supplied chemical form.","findings":[{"id":"form-aware-identification","name":"Form-aware identification","description":"A salt, hydrate, derivative, or complex requires explicit identity mapping.","questions":[{"text":"Do the supplier identifiers describe neutral cyclen or a separately identified salt, hydrate, derivative, or complex?","id":"form-aware-identification-q01","kind":"boundary"},{"text":"Which source supports the mapping between the sample identity and vr.tr.cyclen?","id":"form-aware-identification-q02","kind":"provenance"}]}]}]},{"id":"usable-cyclen-content","name":"Usable cyclen content","description":"Determine how much parent ligand a sample actually supplies.","layers":[{"id":"assay-and-mass-basis","name":"Assay and mass basis","description":"Resolve assay, counterions, water, and solvent contributions.","findings":[{"id":"parent-equivalent-accounting","name":"Parent-equivalent accounting","description":"Cyclen equivalents must use a documented composition and assay basis.","questions":[{"text":"What is the cyclen assay, by which method, and on an as-received or dry basis?","id":"parent-equivalent-accounting-q01","kind":"measurement"},{"text":"How must water, solvent, and any counterions be accounted for when converting sample mass to cyclen moles?","id":"parent-equivalent-accounting-q02","kind":"action"}]}]},{"id":"interfering-impurities","name":"Interfering impurities","description":"Identify contaminants that affect coordination or nitrogen functionalization.","findings":[{"id":"task-relevant-contamination","name":"Task-relevant contamination","description":"Impurity acceptance depends on the intended ligand chemistry.","questions":[{"text":"What residual metals, other amines, or substituted macrocycles are detected, and with what detection limits?","id":"task-relevant-contamination-q01","kind":"measurement"},{"text":"Which impurity limits are required by the intended complexation or derivatization task?","id":"task-relevant-contamination-q02","kind":"action"}]}]}]},{"id":"phase-and-protonation","name":"Phase and protonation","description":"Describe cyclen under the physical and solution conditions in which it will be used.","layers":[{"id":"physical-availability","name":"Physical availability","description":"Record phase, thermal behavior, and dissolution with their conditions.","findings":[{"id":"conditioned-material-properties","name":"Conditioned material properties","description":"Property values must refer to a specified form and measurement environment.","questions":[{"text":"What phase and melting interval are measured for the identified form, and is decomposition observed?","id":"conditioned-material-properties-q01","kind":"measurement"},{"text":"What solubility is supported in the intended solvent at the specified temperature and pH?","id":"conditioned-material-properties-q02","kind":"measurement"}]}]},{"id":"acid-base-speciation","name":"Acid-base speciation","description":"Resolve protonation without treating cyclen as a single-site base.","findings":[{"id":"nitrogen-protonation-evidence","name":"Nitrogen protonation evidence","description":"Stepwise protonation information is needed to interpret donor availability.","questions":[{"text":"Which stepwise protonation constants are supported, using what convention, solvent, temperature, and ionic strength?","id":"nitrogen-protonation-evidence-q01","kind":"provenance"},{"text":"What protonation distribution follows at the intended pH, and how uncertain is that estimate?","id":"nitrogen-protonation-evidence-q02","kind":"measurement"}]}]}]},{"id":"nitrogen-site-use","name":"Nitrogen site use","description":"Assess cyclen as a coordination ligand and a functionalization starting material.","layers":[{"id":"metal-binding","name":"Metal binding","description":"Evaluate a specified metal interaction under explicit conditions.","findings":[{"id":"conditional-complexation","name":"Conditional complexation","description":"Binding claims require a named metal species and evidence for the resulting complex.","questions":[{"text":"For the intended metal and oxidation state, what stoichiometry and formation evidence are available under matching conditions?","id":"conditional-complexation-q01","kind":"provenance"},{"text":"Do proton competition, competing ligands, or formation kinetics limit the proposed use?","id":"conditional-complexation-q02","kind":"action"}]}]},{"id":"covalent-functionalization","name":"Covalent functionalization","description":"Track nitrogen substitution as conversion into a different substance.","findings":[{"id":"substitution-boundary","name":"Substitution boundary","description":"Functionalized products retain a cyclen scaffold but require separate identities.","questions":[{"text":"Are all four parent NH sites present, or does the material already contain protected or substituted nitrogen sites?","id":"substitution-boundary-q01","kind":"measurement"},{"text":"Which separate derivative identity must be linked when the intended substitution changes the parent structure?","id":"substitution-boundary-q02","kind":"boundary"}]}]}]},{"id":"handling-and-release","name":"Handling and release","description":"Determine whether the identified cyclen sample can be handled and released for its intended task.","layers":[{"id":"form-specific-safety","name":"Form-specific safety","description":"Attach applicable hazard and regulatory evidence.","findings":[{"id":"documented-controls","name":"Documented controls","description":"Controls must follow verified documentation without importing classifications from related substances.","questions":[{"text":"Which current SDS and jurisdiction-specific classification apply to this exact form and concentration?","id":"documented-controls-q01","kind":"provenance"},{"text":"What exposure controls, storage conditions, and incompatibilities does that evidence require?","id":"documented-controls-q02","kind":"action"}]}]},{"id":"sample-fitness","name":"Sample fitness","description":"Connect sample history and analytical results to a specific intended use.","findings":[{"id":"release-or-retest","name":"Release or retest","description":"A sample is usable only against explicit task requirements and adequate evidence.","questions":[{"text":"Has storage or handling introduced uncertainty about water content, assay, or metal contamination?","id":"release-or-retest-q01","kind":"provenance"},{"text":"Do the available results justify release for the named task, or which measurements are needed first?","id":"release-or-retest-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 cyclen 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 cyclen 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 cyclen 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 cyclen 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 cyclen 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 cyclen this model covers, and on what evidence?","id":"evidence-neighbours-q01","kind":"provenance"}]}]}]}]},"agentConduct":{"may":["Identify cyclen from analytical data and report the purity and form of a sample.","Describe its use as a ligand and building block for metal complexes, citing sources."],"mustNot":["Handle or describe it as harmless when its safety data shows it is irritant or corrosive.","Present a cyclen-based complex as safe for use in people without approved evidence.","Release amine waste or metal complexes into drains.","Confuse cyclen with its derivatives when reporting results."],"requiresHuman":["Using cyclen or its complexes in any material intended for administration to people or animals.","Disposing of metal complexes made from it."]},"ethics":{"considerations":["Derivatives of cyclen are used in medical imaging agents, so laboratory claims can reach patients.","Waste containing metal complexes can persist in the environment."],"affectedParties":["Laboratory workers","Patients receiving derived agents","Environment near disposal"]},"owners":{"steward":"The laboratory or supplier that holds the material.","roles":[],"masterSystems":[]},"relations":[{"target":"Q100716457","type":"parent","note":"registry parent class"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.cyclen","Wikidata: Q416407 (https://www.wikidata.org/wiki/Q416407)"]},"properties":{"applicability":"required","items":["Parent connectivity: Saturated 12-membered ring; four NH sites separated by ethylene groups","Chemical form: Free base; identified salt; hydrate or solvate; solution; unresolved","Parent molar mass: 172.27 g/mol for neutral C8H20N4","Cyclen assay: Mass % or mol/kg; method and as-received or dry basis required","Water and residual solvent: Mass %; identified solvent; analytical method","Physical and thermal state: Observed phase at stated temperature; melting interval in °C; decomposition flag","Solubility: g/L or mol/L with solvent, temperature, pH, and chemical form","Protonation state: Species fractions or mean protonation; pH, solvent, temperature, and ionic strength","Metal contamination: Element-specific mg/kg or mol/mol cyclen, with detection limits","Coordination evidence: Metal species, stoichiometry, linked complex identity, and condition-specific equilibrium or kinetic evidence","Safety and regulatory evidence: Applicable SDS, revision date, jurisdiction, chemical form, and verified inventory identifiers"]},"recognition":{"applicability":"required","items":["A white to off-white crystalline solid that cannot be identified by appearance.","Identity is settled by spectroscopy and melting point against a reference."]},"capabilities":{"applicability":"required","items":["Check structural and identifier evidence before accepting a sample as cyclen.","Calculate available cyclen equivalents from assay and salt or solvate composition.","Assess whether a specified solvent and pH support the intended preparation.","Evaluate suitability for a named metal-coordination task using contamination and speciation evidence.","Assess whether nitrogen sites are available for a proposed derivatization and link the resulting derivative separately.","Select handling and storage controls from documentation applicable to the sample form."]},"hazards":{"applicability":"required","items":["Skin and eye irritation or burns from handling.","Contamination of products with unreacted ligand or free metal."]},"interfaces":{"applicability":"required","items":["Globally Harmonized System of Classification and Labelling of Chemicals (GHS), United Nations."]},"context":{"applicability":"required","items":["Cyclen is encountered in coordination chemistry and synthetic laboratories as a macrocyclic ligand and chemical building block.","Its derivatives are used to develop metal-binding systems for applications such as imaging research, sensing and radiochemistry, with performance depending on the attached groups and coordinated metal."]}},"sources":[{"title":"Wikidata item Q416407: cyclen","url":"https://www.wikidata.org/wiki/Q416407","note":"identity and sense of the item"},{"title":"Wikipedia: Cyclen","url":"https://en.wikipedia.org/wiki/Cyclen","note":"general description of the item"}],"openQuestions":["Which authoritative sources establish cyclen's EC number, applicable hazard classifications, and any substance-specific exposure limits in the intended jurisdiction?","Which melting, boiling or decomposition, and solubility measurements are reliable for the anhydrous free base rather than a salt or hydrate?","Which stepwise protonation constants and uncertainty estimates should be used for the intended solvent, temperature, and ionic strength?","Which metal-specific equilibrium and kinetic measurements justify the intended coordination use?","What assay, water, and trace-metal acceptance limits are necessary for the target application, and what storage evidence supports a retest interval?"],"resources":{"spec":"/models/things/publications/thing-q416407/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q416407/spec.json"],"providers":["Codex"],"researchStatus":"unreviewed","generatedAt":"2026-09-12T08:58:05Z","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 2026-10-07T10:10:30+00:00: completeness 1.00; sense: Wikidata description; 2 live sources; review by codex: pass"},"score":1.0}}