cyclen
Enable an agent to identify cyclen, assess the chemical form and quality of a sample, and determine its suitability for coordination or derivatization work.
Bundle → Layer → Finding → Questions Filled
6 bundles · 11 layers · 16 findings · 26 questions
Macrocycle identity Establish the parent ring and separate it from related chemical entities.
Ring connectivity
Verify the defining nitrogen arrangement and unsubstituted parent structure.
Parent structure evidence
Recognition requires evidence consistent with the 12-membered tetraamine ring.
- Does the assigned structure contain four NH sites at positions 1, 4, 7, and 10 with ethylene spacers? definition
- Which analytical evidence distinguishes the sample from ring-size analogues or substituted cyclen? measurement
Chemical entity boundaries
Separate the parent reference identity from the supplied chemical form.
Form-aware identification
A salt, hydrate, derivative, or complex requires explicit identity mapping.
- Do the supplier identifiers describe neutral cyclen or a separately identified salt, hydrate, derivative, or complex? boundary
- Which source supports the mapping between the sample identity and vr.tr.cyclen? provenance
Usable cyclen content Determine how much parent ligand a sample actually supplies.
Assay and mass basis
Resolve assay, counterions, water, and solvent contributions.
Parent-equivalent accounting
Cyclen equivalents must use a documented composition and assay basis.
- What is the cyclen assay, by which method, and on an as-received or dry basis? measurement
- How must water, solvent, and any counterions be accounted for when converting sample mass to cyclen moles? action
Interfering impurities
Identify contaminants that affect coordination or nitrogen functionalization.
Task-relevant contamination
Impurity acceptance depends on the intended ligand chemistry.
- What residual metals, other amines, or substituted macrocycles are detected, and with what detection limits? measurement
- Which impurity limits are required by the intended complexation or derivatization task? action
Phase and protonation Describe cyclen under the physical and solution conditions in which it will be used.
Physical availability
Record phase, thermal behavior, and dissolution with their conditions.
Conditioned material properties
Property values must refer to a specified form and measurement environment.
- What phase and melting interval are measured for the identified form, and is decomposition observed? measurement
- What solubility is supported in the intended solvent at the specified temperature and pH? measurement
Acid-base speciation
Resolve protonation without treating cyclen as a single-site base.
Nitrogen protonation evidence
Stepwise protonation information is needed to interpret donor availability.
- Which stepwise protonation constants are supported, using what convention, solvent, temperature, and ionic strength? provenance
- What protonation distribution follows at the intended pH, and how uncertain is that estimate? measurement
Nitrogen site use Assess cyclen as a coordination ligand and a functionalization starting material.
Metal binding
Evaluate a specified metal interaction under explicit conditions.
Conditional complexation
Binding claims require a named metal species and evidence for the resulting complex.
- For the intended metal and oxidation state, what stoichiometry and formation evidence are available under matching conditions? provenance
- Do proton competition, competing ligands, or formation kinetics limit the proposed use? action
Covalent functionalization
Track nitrogen substitution as conversion into a different substance.
Substitution boundary
Functionalized products retain a cyclen scaffold but require separate identities.
- Are all four parent NH sites present, or does the material already contain protected or substituted nitrogen sites? measurement
- Which separate derivative identity must be linked when the intended substitution changes the parent structure? boundary
Handling and release Determine whether the identified cyclen sample can be handled and released for its intended task.
Form-specific safety
Attach applicable hazard and regulatory evidence.
Documented controls
Controls must follow verified documentation without importing classifications from related substances.
- Which current SDS and jurisdiction-specific classification apply to this exact form and concentration? provenance
- What exposure controls, storage conditions, and incompatibilities does that evidence require? action
Sample fitness
Connect sample history and analytical results to a specific intended use.
Release or retest
A sample is usable only against explicit task requirements and adequate evidence.
- Has storage or handling introduced uncertainty about water content, assay, or metal contamination? provenance
- Do the available results justify release for the named task, or which measurements are needed first? action
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Check these first
Recalled without web access and unsourced; every item is a lead to verify.
- Which of these check these first hold for the sense of cyclen this model covers, and on what evidence? provenance
Identifiers and schemes
Recalled without web access and unsourced; every item is a lead to verify.
- Which of these identifiers and schemes hold for the sense of cyclen this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Which of these real-world use hold for the sense of cyclen this model covers, and on what evidence? provenance
Typical measurements
Recalled without web access and unsourced; every item is a lead to verify.
- Which of these typical measurements hold for the sense of cyclen this model covers, and on what evidence? provenance
Failure modes and hazards
Recalled without web access and unsourced; every item is a lead to verify.
- Which of these failure modes and hazards hold for the sense of cyclen this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Recalled without web access and unsourced; every item is a lead to verify.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of cyclen this model covers, and on what evidence? provenance
Classifiers Filled
- Family
- Thing Registry
- Category
- Physical world and living systems
- Entry kind
- thing
- Plane
- PHY
- Domain
- PHY.MAT
What it is Filled
Cyclen is 1,4,7,10-tetraazacyclododecane, a saturated twelve-membered macrocyclic amine with formula C8H20N4 whose four nitrogen atoms can coordinate metal ions.
In scope
- 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 of scope
- 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
Why it exists Filled
Enable an agent to identify cyclen, assess the chemical form and quality of a sample, and determine its suitability for coordination or derivatization work.
Distinguishing features Filled
- 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)
What robots and AI may and may not do Filled
Must not
- 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.
Only with a human decision
- Using cyclen or its complexes in any material intended for administration to people or animals.
- Disposing of metal complexes made from it.
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.
Moral aspects Filled
- Derivatives of cyclen are used in medical imaging agents, so laboratory claims can reach patients.
- Waste containing metal complexes can persist in the environment.
Who is affected
- Laboratory workers
- Patients receiving derived agents
- Environment near disposal
Owners Filled
Steward
The laboratory or supplier that holds the material.
Links to other meta-models Filled
parent
- Q100716457 - registry parent class
What else AI and robots need to interact with it Filled
Identity and identifiers required Filled
- Vercy registry: vr.tr.cyclen
- Wikidata: Q416407 (https://www.wikidata.org/wiki/Q416407)
Direct properties required Filled
- 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 required Filled
- 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 and actions required Filled
- 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 and failure modes required Filled
- Skin and eye irritation or burns from handling.
- Contamination of products with unreacted ligand or free metal.
Standards and interfaces required Filled
- Globally Harmonized System of Classification and Labelling of Chemicals (GHS), United Nations.
Context of use required Filled
- 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 Filled
- Wikidata item Q416407: cyclen - identity and sense of the item
- Wikipedia: Cyclen - general description of the item
Open questions
- 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?
Machine files
Provenance
thing registry research (pass 2) · unreviewed
Built from: models/things/publications/thing-q416407/spec.json