FTIR ANALYSIS REPORT

Spectrum Analysis Result

No.: 20260509231605301821550 Date: 2026-05-09 23:20:03 Reported by: FTIR.fun Contact: [email protected]

Download a professional, formatted PDF of this analysis.

Executive conclusion

aromatic polyester material

Class / direction

Moderate confidence

#691 Initial rank 1 Current rank 1 Library lead match 86.9%

Key Findings

Library found a dense cluster of polyester references among the top candidates, with Poly(ethylene terephthalate) at 0.874 similarity, PTT at 0.869, and PBT at 0.836 — implication: the retrieval pattern supports a terephthalate/polyester family rather than an isolated small molecule.
LLM found a strong 1723 cm-1 carbonyl together with C-O-region bands at 1256, 1121, 1102, and 1019 cm-1 and assigned an ester-containing organic material direction at 0.78 confidence — implication: the observed spectrum is consistent with an ester-rich organic backbone.
Spectral feature at 1723 cm-1 is present — assignment: ester carbonyl, supporting a polyester-type material rather than a hydrocarbon or purely inorganic phase.
KG found only a broad oxygen-containing direction at 0.40 confidence, and its literature-backed support is limited to peak 873 cm-1 with one source — implication: KG does not provide specific class-level discrimination here [1].
Axis A and Axis B agree on oxygenated ester chemistry but disagree on specificity: Library and LLM support an organic ester/polyester interpretation, while KG remains broad and low-confidence — impact: confidence supports class-level resolution but not entity-level identification.
Efficient next verification: Prioritize KG and literature enrichment for uncovered peaks 1102 because those missing anchors are currently blocking graph-side confirmation.; Use discriminative bands around 1723, 1256, 1121, 1102, 1019, 2974 to decide between the LLM-supported ester-containing organic material direction and the KG-supported oxygen containing direction.

Spectrum comparison

aromatic polyester material library vs. sample

Loading comparison...

Library reference spectrum overlaid with uploaded sample spectrum — Figure 1. Overlay of aromatic polyester material (library entry, background) and the uploaded sample spectrum (teal curve). Visual alignment degree reflects the reported similarity score.

Evidence

Conclusion evidence

Only evidence already present in the current result contract is shown here.

Library lead candidate LIB

aromatic polyester material #691 | match 86.9%

Material direction AGG

ester-containing organic material Likely material direction: ester-containing organic material (74% support).

Supporting peaks

1723 cm-1 1256 cm-1 1121 cm-1 1102 cm-1 1019 cm-1 2974 cm-1 873 cm-1 971 cm-1

Supporting groups

ester c_o alkyl_c_h acetyl aldehyde amide anhydride borate

Peak reading

Characteristic peak interpretation

Each peak is rewritten as a single readable sentence. KG rows show literature citation labels, and LLM rows show the current LLM confidence tier.

Wavenumber	One-line interpretation	KG citation	LLM confidence
1723	1723 cm-1: possible source: ester-containing organic material; KG hint: carboxyl; aromatic.	[1]	Moderate confidence
1256	1256 cm-1: possible source: ester-containing organic material; KG hint: carboxyl; aromatic.	[1]	Moderate confidence
1102	1102 cm-1: possible source: ester-containing organic material; phosphate-related inorganic contribution.	-	Moderate confidence
1121	1121 cm-1: possible source: ester-containing organic material; KG hint: carboxyl; aromatic.	[1]	Moderate confidence
1341	1341 cm-1: possible source: carboxyl; aromatic.	[1]	-
1019	1019 cm-1: possible source: ester-containing organic material; phosphate-related inorganic contribution; KG hint: carboxyl; aromatic.	[1]	Moderate confidence
1410	1410 cm-1: possible source: carbonate-containing organic/mineral mixture; KG hint: carboxyl; aromatic.	[1]	Moderate confidence
873	873 cm-1: possible source: carbonate-containing organic/mineral mixture; KG hint: carboxyl; aromatic.	[1]	Moderate confidence
1506	1506 cm-1: possible source: carboxyl; aromatic.	[1]	-
1457	1457 cm-1: possible source: carboxyl; aromatic.	[1]	-
971	971 cm-1: possible source: phosphate-related inorganic contribution; KG hint: carboxyl; aromatic.	[1]	Moderate confidence
2974	2974 cm-1: possible source: ester-containing organic material; KG hint: carboxyl; aromatic.	[1]	Moderate confidence

Reasoning

Reasoning chain

This section explains how the current conclusion was reached from the available evidence.

Aromatic polyester material was selected because the most decisive quantified evidence is the library’s polyester cluster led by Poly(ethylene terephthalate) at 87.4% similarity, reinforced by the LLM ester-pattern assignment at 0.78 confidence; the next-best alternative, the top specific small-molecule library hit at 88.7%, was not selected because it lacks corroboration from the other axes and is too narrowly assigned relative to the broader polyester retrieval pattern.
The nearest library entity is stable, but class-level corroboration is less complete.
Likely material direction: ester-containing organic material (74% support).
Recommended candidate: (2R,3S,4S,5R,6S)-2-(hydroxymethyl)-6-(2-phenylethylsulfanyl)oxane-3,4,5-triol (#691) with a current matching score of 0.869.
The resolved conclusion is an aromatic polyester material, supported at moderate confidence (0.77). Library retrieval provides the strongest quantified evidence through polyester-like matches clustered just below the top hit, including Poly(ethylene terephthalate) at 87.4% similarity, additional PET entries at 86.8% and 85.4%, PTT at 86.9% and 84.3%, and PBT at 83.6%, while the LLM independently assigns an ester-containing organic material direction with 0.78 confidence from the 1723 cm-1 carbonyl and multiple C-O bands at 1256, 1121, 1102, and 1019 cm-1. Library and LLM therefore converge on an ester-based polymeric interpretation, whereas KG remains low-confidence (0.40) and nonspecific at the broad oxygen-containing level. The primary limiting factor is that the highest-ranked library hit is a specific small-molecule retrieval at 88.7% similarity with only a 0.003 lead over a non-entity spectral entry, so the data do not justify assignment to a specific named substance.
Library retrieval keeps (2R,3S,4S,5R,6S)-2-(hydroxymethyl)-6-(2-phenylethylsulfanyl)oxane-3,4,5-triol (#691) as the nearest match.
KG derives the material direction oxygen containing from group-level evidence. top graph recall is spectrum #11865. 1 literature source(s) reinforce this path; groups carbon_dioxide, carboxyl, group_iiia_element, hydroxyl; peaks 873.. semantic bridge links the current direction to known directions such as "N-(4-Hydroxyphenyl)acetamide", "N-(4-Hydroxyphenyl)acetamide". secondary component clues remain visible through carbonyl like, main group element containing.
The strongest pattern is a prominent carbonyl at 1723 cm-1 together with multiple strong C-O region bands at 1256, 1121, 1102, and 1019 cm-1 plus weak alkyl C-H near 2974 cm-1, which is most consistent with an ester- or acrylic/vinyl-ester-like organic material direction. This is more directly supported by the peak pattern than mineral-only interpretations.
Peak notes: 1723: LLM: ester-containing organic material | KG: carboxyl; aromatic; 1256: LLM: ester-containing organic material | KG: carboxyl; aromatic; 1102: LLM: ester-containing organic material; phosphate-related inorganic contribution; 1121: LLM: ester-containing organic material | KG: carboxyl; aromatic.

Risk

Uncertainty and blockers

These items limit how far the current conclusion can be trusted or refined.

Independent LLM flags conflicting groups: phosphate, carbonate
dual-axis confidence 0.400 is below dynamic threshold 0.780
LLM/KG agreement 0.075 is below 0.600
Library lead over the runner-up remains narrow (gap 0.000)
KG limit: graph fact coverage is missing for observed peaks: 1102
KG limit: KG co-occurrence evidence was skipped for this high-peak-count sample: compressed graph peak count 11 exceeds FTIRFUN_KG_GRAPH_CONTEXT_COOCCURRENCE_MAX_PEAKS=10; window/pair co-occurrence SQL was skipped and only direct peak-group facts were used
graph fact coverage is missing for observed peaks: 1102
KG co-occurrence evidence was skipped for this high-peak-count sample: compressed graph peak count 11 exceeds FTIRFUN_KG_GRAPH_CONTEXT_COOCCURRENCE_MAX_PEAKS=10; window/pair co-occurrence SQL was skipped and only direct peak-group facts were used
Add or derive project facts around currently uncovered peaks.

Recommendation

Recommended next steps

These are the next verification actions suggested by the current reasoning output.

Prioritize KG and literature enrichment for uncovered peaks 1102 because those missing anchors are currently blocking graph-side confirmation.
Use discriminative bands around 1723, 1256, 1121, 1102, 1019, 2974 to decide between the LLM-supported ester-containing organic material direction and the KG-supported oxygen containing direction.
Compare the library lead against the nearest runner-up explicitly because the current lead gap is only 0.000.

Mixture

Component and mixture notes

When present, mixture or component-peeling diagnostics are summarized here.

Two-component formulation analysis is paused because the current library does not have enough coverage for reliable formulation-level inference.
The old two-component code path is kept in the repository, but the runtime no longer uses it to avoid pushing the search toward unsupported composition claims.
Component peeling is paused in runtime because conservative low-match replay did not produce verified wins after excluding self-peeling.
The exploration was still useful: relaxing the gates restored peelability, but most new extractions were self-peeling or chemically implausible, which clarified the current boundary of the library and gating design.
The peeling implementation remains in the repository for later reactivation after stronger low-match evidence appears.

Literature

References

Knowledge-graph literature citations used to support the spectral assignment.

1 literature source(s) reinforce this path; groups carbon_dioxide, carboxyl, group_iiia_element, hydroxyl; peaks 873.

[1] 10.1039/d2ra01798a

Supports: 873 cm

Reference workbench

Curve comparison and library verification

Use the workbench below to manually verify the report conclusion against the selected library curves and Top15 candidates.

Library spectrum loads when this workbench opens.

Move across the sample curve to inspect your sample values.

Library spectrum Interactive sample curve Move the pointer to show the vertical guide line.

Top 15 candidates

Reference library candidates

This list is a verification appendix. It helps you compare nearby candidates without repeating the report conclusion.

Rank	Match %	Compound Name	Formula / SMILES	Library preview	Action
Reference candidates load when this verification workbench opens.

Appendix A

Detected peak table

All detected peaks are kept here as a single appendix instead of being repeated across multiple cards.

Index	Wavenumber	Transmittance (%)	Sources	One-line interpretation	KG citation	LLM confidence
1	1723	0.99	LLM / KG	1723 cm-1: possible source: ester-containing organic material; KG hint: carboxyl; aromatic.	[1]	Moderate confidence
2	1256	0.69	LLM / KG	1256 cm-1: possible source: ester-containing organic material; KG hint: carboxyl; aromatic.	[1]	Moderate confidence
3	1102	0.44	LLM	1102 cm-1: possible source: ester-containing organic material; phosphate-related inorganic contribution.	-	Moderate confidence
4	1121	0.36	LLM / KG	1121 cm-1: possible source: ester-containing organic material; KG hint: carboxyl; aromatic.	[1]	Moderate confidence
5	1341	0.17	KG	1341 cm-1: possible source: carboxyl; aromatic.	[1]	-
6	1019	0.16	LLM / KG	1019 cm-1: possible source: ester-containing organic material; phosphate-related inorganic contribution; KG hint: carboxyl; aromatic.	[1]	Moderate confidence
7	1410	0.13	LLM / KG	1410 cm-1: possible source: carbonate-containing organic/mineral mixture; KG hint: carboxyl; aromatic.	[1]	Moderate confidence
8	873	0.05	LLM / KG	873 cm-1: possible source: carbonate-containing organic/mineral mixture; KG hint: carboxyl; aromatic.	[1]	Moderate confidence
9	1506	0.05	KG	1506 cm-1: possible source: carboxyl; aromatic.	[1]	-
10	1457	0.03	KG	1457 cm-1: possible source: carboxyl; aromatic.	[1]	-
11	971	0.03	LLM / KG	971 cm-1: possible source: phosphate-related inorganic contribution; KG hint: carboxyl; aromatic.	[1]	Moderate confidence
12	2974	0.03	LLM / KG	2974 cm-1: possible source: ester-containing organic material; KG hint: carboxyl; aromatic.	[1]	Moderate confidence

Appendix B

Sample information and raw spectrum

The raw uploaded spectrum is retained here for audit and manual review.

Baseline correction method: Asymmetric Least Squares Smoothing

The wavelength range for analysis(cm-1): [(400, 4000)]

Raw spectrum without baseline correction or other processing:

Results20260509231605301821550