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aromatic nitrile-amide-methacrylate organic material

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Số kết quả: 20260211052953017893659 Chủ sở hữu: sjh Bình luận: 0
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FTIR ANALYSIS REPORT

FTIR Spectrum Analysis Report

No.: 20260211052953017893659 Date: Reported by: FTIR.fun Contact: [email protected]

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Top15

Similarity-ranked Top-15 library comparison

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Top 15 candidates

Reference library candidates

Rank Match % Compound Name Formula / SMILES Library preview Action
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Based on the library matches and evidence above.

Conclusion

aromatic nitrile-amide-methacrylate organic material

General assessment
Độ tin cậy LLM
#81561 Current rank 1 Library lead match 60.9%
Conclusion
  1. The presence of aromatic C–H, amide III, and alkyl C–H bands is corroborated by multiple literature reports that assign analogous peaks in similar polymeric systems.
  2. The band at 1237 cm⁻¹ is assigned to amide III (C–N–H bending), consistent with polyamide or proteinaceous structures [8].
  3. Bands at 1280 cm⁻¹ and 1303 cm⁻¹ are attributable to alkyl C–H bending modes, indicating saturated hydrocarbon chains [12,6].
Main limitation

The nearest library match is aluminum azanium disulfate dodecahydrate (spectral similarity 0.629), a hydrated inorganic salt. No bands characteristic of sulfate, ammonium, or aluminum–oxygen vibrations are evident. The library’s ‘aromatic/methacrylate’ direction, derived from the Top‑15 consensus, better reflects the observed organic functional groups.

Evidence & interpretation
Evidence

Key evidence

Kết quả khớp hàng đầu từ thư viện
aluminum azanium disulfate dodecahydrate #81561 | match 60.9%
Hướng vật liệu
aromatic nitrile-amide-methacrylate organic material The FTIR spectrum indicates the sample is an organic compound featuring aromatic rings, nitrile, amide, and ester (methacrylate‑type) functionalities. The spectral evidence aligns with a nitrogen‑rich aromatic polymer or copolymer, while the best‑matching library reference (aluminum azanium disulfate dodecahydrate) is inconsistent with the observed bands, reflecting a low‑confidence library match.
Supporting peaks
724 cm-1 748 cm-1 891 cm-1 983 cm-1 1237 cm-1 1280 cm-1 1303 cm-1 1378 cm-1
Supporting groups
nitrile aromatic methyl amide n_h o_c_o aromatic_c_h
Support

Evidence supporting the conclusion

Only sample-relevant statements that support the present conclusion are shown here.

  1. The FTIR spectrum indicates the sample is an organic compound featuring aromatic rings, nitrile, amide, and ester (methacrylate‑type) functionalities. The spectral evidence aligns with a nitrogen‑rich aromatic polymer or copolymer, while the best‑matching library reference (aluminum azanium disulfate dodecahydrate) is inconsistent with the observed bands, reflecting a low‑confidence library match.
  2. The presence of aromatic C–H, amide III, and alkyl C–H bands is corroborated by multiple literature reports that assign analogous peaks in similar polymeric systems.
  3. The band at 1237 cm⁻¹ is assigned to amide III (C–N–H bending), consistent with polyamide or proteinaceous structures [8].
  4. Bands at 1280 cm⁻¹ and 1303 cm⁻¹ are attributable to alkyl C–H bending modes, indicating saturated hydrocarbon chains [12,6].
  5. The region 3080–3222 cm⁻¹ shows multiple absorptions characteristic of aromatic C–H stretching vibrations, confirming the presence of aromatic moieties.
  6. A sharp band at 2210 cm⁻¹ corresponds to the nitrile (C≡N) stretch, commonly observed in nitrile‑containing polymers and small molecules.
  7. The intense band at 1688 cm⁻¹ is assigned to ester (methacrylate‑type) C=O stretching, supporting the ester functionality indicated by the library consensus.
  8. The carbonyl amide I band at 1628 cm⁻¹ further substantiates the amide group assignment, overlapping with the ester carbonyl.
  9. Aliphatic C–H stretching bands near 2903 cm⁻¹ and 2944 cm⁻¹ reflect methylene and methyl groups, while a weaker band at 724 cm⁻¹ suggests long‑chain aliphatic structures or aromatic out‑of‑plane bending.
  10. Major peak assignments include 3892: Quality: The spectrum edges look truncated or baseline-shifted; 3664: Quality: The spectrum edges look truncated or baseline-shifted; 2944: Related literature: aliphatic C–H stretch (methylene/methyl) | Quality: The spectrum edges look truncated or baseline-shifted; 2990: Related literature: aliphatic C–H stretch (methylene/methyl) | Quality: The spectrum edges look truncated or baseline-shifted.
Limitations

Evidence that limits the conclusion

  • The nearest library match is aluminum azanium disulfate dodecahydrate (spectral similarity 0.629), a hydrated inorganic salt. No bands characteristic of sulfate, ammonium, or aluminum–oxygen vibrations are evident. The library’s ‘aromatic/methacrylate’ direction, derived from the Top‑15 consensus, better reflects the observed organic functional groups.
  • The spectrum displays features attributable to aromatic C–H, amide, nitrile, and ester groups simultaneously, suggesting a possible mixture, copolymer, or functionalized material. The exact molecular identity remains unresolved, and assignments of some fingerprint bands are tentative.
Recommendation

Suggested next verification

  • For definitive identification, combine with complementary techniques such as pyrolysis‑GC‑MS, NMR spectroscopy, or elemental analysis.
  • If a polymer, consider solvent extraction or chromatographic separation to isolate components for further spectroscopic analysis.
Peak analysis

Detected peaks and interpretation

★ = Literature-supported peak assignment.

Index Characteristic Wavenumber Absorbance Evidence One-line interpretation Citation Confidence
1 · 3892 1.00 - - - -
2 · 3664 1.00 - - - -
3 · 2944 1.00 - - - -
4 · 2990 1.00 - - - -
5 ★ 3080 1.00 Gán hỗ trợ bởi tài liệu Dải tại 3080 cm-1 được gán cho aromatic C-H stretching[90][S3]. [90], [S3] Độ tin cậy tổng thể
6 · 3509 1.00 - - - -
7 · 3551 1.00 - - - -
8 · 3579 1.00 - - - -
9 · 2860 1.00 - - - -
10 · 3611 1.00 - - - -
11 · 3623 1.00 - - - -
12 · 3637 1.00 - - - -
13 · 3597 1.00 - - - -
14 · 3684 1.00 - - - -
15 · 3726 1.00 - - - -
16 · 3756 1.00 - - - -
17 · 3780 1.00 - - - -
18 · 3809 1.00 - - - -
19 · 3873 1.00 - - - -
20 · 3696 1.00 - - - -
21 · 3843 1.00 - - - -
22 · 3497 1.00 - - - -
23 · 3531 0.99 - - - -
24 · 3856 0.99 - - - -
25 · 3442 0.97 - - - -
26 · 3709 0.97 - - - -
27 · 3125 0.96 - - - -
28 · 3287 0.96 - - - -
29 · 3051 0.95 - - - -
30 · 3222 0.95 - - - -
31 · 2877 0.95 - - - -
32 · 3110 0.95 - - - -
33 · 3179 0.95 - - - -
34 · 3827 0.95 - - - -
35 · 3158 0.94 - - - -
36 · 3021 0.94 - - - -
37 · 3381 0.94 - - - -
38 · 3095 0.94 - - - -
39 ★ 2903 0.94 Gán văn học tương tự Dải tại 2903 cm-1 được gán cho aliphatic C–H stretch (methylene/methyl)[91][S5]. [91], [S5] Độ tin cậy tổng thể
40 · 3010 0.94 - - - -
41 · 3210 0.93 - - - -
42 · 3459 0.92 - - - -
43 · 3410 0.90 - - - -
44 · 3253 0.90 - - - -
45 · 3233 0.89 - - - -
46 · 2750 0.89 - - - -
47 · 3144 0.88 - - - -
48 · 3038 0.88 - - - -
49 · 2586 0.88 - - - -
50 · 3421 0.87 - - - -
51 · 2787 0.87 - - - -
52 · 2650 0.86 - - - -
53 · 3339 0.86 - - - -
54 · 3304 0.86 - - - -
55 ★ 3198 0.86 Gán hỗ trợ bởi tài liệu Dải tại 3198 cm-1 được gán cho aromatic C-H stretching[90][S3]. [90], [S3] Độ tin cậy tổng thể
56 · 2711 0.85 - - - -
57 · 3273 0.85 - - - -
58 · 2632 0.85 - - - -
59 · 2495 0.85 - - - -
60 · 2671 0.85 - - - -
61 · 2564 0.84 - - - -
62 · 3324 0.84 - - - -
63 · 3363 0.83 - - - -
64 · 2335 0.82 - - - -
65 · 2827 0.81 - - - -
66 · 2526 0.81 - - - -
67 · 2808 0.81 - - - -
68 · 2353 0.80 - - - -
69 · 2471 0.79 - - - -
70 · 2408 0.78 - - - -
71 · 2419 0.78 - - - -
72 · 2385 0.78 - - - -
73 · 2308 0.78 - - - -
74 ★ 2210 0.77 Gán hỗ trợ bởi tài liệu Dải tại 2210 cm-1 được gán cho nitrile[92]. [92] Độ tin cậy tổng thể
75 · 2258 0.76 - - - -
76 · 2125 0.74 - - - -
77 · 2154 0.74 - - - -
78 · 2027 0.72 - - - -
79 · 2002 0.71 - - - -
80 · 1952 0.69 - - - -
81 · 1815 0.65 - - - -
82 · 1785 0.63 - - - -
83 ★ 1688 0.53 Gán hỗ trợ bởi tài liệu Dải tại 1688 cm-1 được gán cho ester[88]. [88] Độ tin cậy tổng thể
84 · 1464 0.51 - - - -
85 · 1499 0.48 - - - -
86 · 1515 0.45 - - - -
87 ★ 1303 0.45 Gán hỗ trợ bởi tài liệu Dải tại 1303 cm-1 được gán cho alkyl C-H[87]. [87] Độ tin cậy LLM
88 ★ 1628 0.45 Gán hỗ trợ bởi tài liệu Dải tại 1628 cm-1 được gán cho amide[95]. [95] Độ tin cậy tổng thể
89 ★ 1280 0.43 Gán hỗ trợ bởi tài liệu Dải tại 1280 cm-1 được gán cho alkyl C-H[96]. [96] Độ tin cậy LLM
90 · 1378 0.39 - - - -
91 · 891 0.32 - - - -
92 · 748 0.28 - - - -
93 · 983 0.27 - - - -
94 ★ 724 0.26 Gán hỗ trợ bởi tài liệu Dải tại 724 cm-1 được gán cho alkyl C-H[94]. [94] Độ tin cậy LLM
95 ★ 1237 0.25 Gán hỗ trợ bởi tài liệu Dải tại 1237 cm-1 được gán cho amide[93]. [93] Độ tin cậy LLM
Literature

References

2384 local KG peak-level literature source(s) kept in the candidate pool; peaks 724, 748, 891, 983, 1237, 1280; groups (v_v), 1,3_substituted_compound, 1_so, 2,4,6_carbon_radial.

No. Title DOI Page
[1] Pulyalina 等 - 2022 - Effect of ionic liquid on formation of copolyimide 10.1038/s41598-022-12377-0 -
[2] Bharudin 等 - 2013 - Condensed Tannins from Acacia Mangium Bark Charac 10.1063/1.4858646 -
[3] Pandey 等 - 2016 - Impact of post deposition annealing in O-2 ambient 10.1016/j.optmat.2014.08.005 -
[4] Ngo 等 - 2020 - Improvement of Hydrophilicity for Polyamide Compos 10.1155/2020/6641225 -
[5] Hamouda 等 - 2020 - Bioprocessing strategies for cost-effective simult 10.1038/s41598-020-70251-3 -
[6] Hagemann 等 - 2018 - Portable combination of Fourier transform infrared 10.1039/c8an01192c -
[7] Gao 等 - 2020 - A novel synthetic chitosan selenate (CS) induces a 10.1016/j.ijbiomac.2020.05.016 -
[8] Fouda 等 - 2022 - Investigate the role of fungal communities associa 10.1038/s41529-022-00296-4 -
[9] Cebi - 2021 - Quantification of the Geranium Essential Oil, Palm 10.3390/foods10081848 -
[10] Baldassarre 等 - 2020 - Crystal Chemistry and Luminescence Properties of E 10.3390/cryst10040250 -
[11] Ashby 等 - 2013 - The effect of alkyl chain length on the level of c 10.1007/s11051-013-1425-8 -
[12] Arya 和 Sharma - 2018 - Structural, microstructural and electrochemical pr 10.1007/s11581-017-2364-7 -
[13] Armenta 等 - 2005 - FTIR approaches for diuron determination in commer 10.1021/jf050268f -
[14] Mino 等 - 2014 - CO2 Capture by TiO2 Anatase Surfaces A Combined D 10.1021/jp507443k -
[15] Zuena 等 - 2022 - Portrait of an artist at work exploring Max Ernst 10.1186/s40494-022-00777-4 -
[16] Yan 等 - 2019 - The behavior of ozone on different iron oxides sur 10.1038/s41598-019-50910-w -
[17] Worzakowska - 2016 - Starch-g-poly(benzyl methacrylate) copolymers Char 10.1007/s10973-016-5328-7 -
[18] Wang 等 - 2022 - Biosynthesis and Structural Characterization of Le 10.21203/rs.3.rs-511002/v2 -
[19] Wang 等 - 2018 - Developing Effective Separation of Feldspar and Qu 10.3390/min8040149 -
[20] Wang 等 - 2015 - The improved Hydrogen Storage Performances of the 10.3390/en8076898 -
[21] Sun 等 - 2020 - Electrosprayed Polymeric Nanospheres for Enhanced 10.2147/ijn.s235146 -
[22] Simic 等 - 2022 - A Mechanism Assessment and Differences of Cadmium 10.3390/pr10101957 -
[23] Rysiakiewicz-Pasek 等 - 2020 - New Insight into Phase Transitions of Porous Glass 10.3390/ma13173698 -
[24] Rozenberg 等 - 2004 - Low temperature FTIR spectroscopy and hydrogen bon 10.1016/s1386-1425(03)00251-8 -
[25] Ristova 等 - 2005 - Effect of long-term He-Ne laser light exposure and 10.1088/0268-1242/20/10/004 -
[26] Rasko 和 Kiss - 2006 - Interaction of acetonitrile with oxygen on TiO2-su 10.1007/s10562-006-0059-1 -
[27] Raghav 等 - 2017 - Nonenzymatic glycosylation of human serum albumin 10.1371/journal -
[28] Prathyusha 等 - 2018 - Chemical characterization and antioxidant properti 10.1016/j.btre.2018.e00277 -
[29] Peng 等 - 2013 - Functionalization of Graphene with Nitrile Groups 10.1155/2013/841789 -
[30] Panda 等 - 2020 - Heavy metal removal from water by adsorption using 10.1007/s11356-020-08482-0 -
[31] Odigbo 等 - 2023 - Polyethylene terephthalate (PET) biodegradation by 10.21203/rs.3.rs-2044624/v1 -
[32] Nwokolo 等 - 2022 - Synthesis, Characterization and Investigation of A 10.3390/coatings12091288 -
[33] Niu 等 - 2022 - Hyaluronic Acid Micelles for Promoting the Skin Pe 10.2147/ijn.s372711 -
[34] Naseem 等 - 2020 - Mesoporous ZnAl2Si10O24 nanofertilizers enable hig 10.1038/s41598-020-67611-4 -
[35] Ma 等 - 2022 - Thermal and Rheological Performances Evaluation of 10.3390/molecules27227776 -
[36] Lu 和 Mi - 2005 - Characterization of the interfacial interaction be 10.1021/ma0486896 -
[37] Lee 等 - 2019 - Adsorption properties of arsenic on sulfated TiO2 10.1016/j.jiec.2019.08.024 -
[38] Lee 等 - 2008 - Surface-initiated ring-opening polymerization of p 10.1002/pola.22457 -
[39] Kudzin 等 - 2019 - Biofunctionalization of Textile Materials.1. Biofu 10.3390/coatings9070412 -
[40] Krol 等 - 2021 - Polyurethane cationomers containing fluorinated so 10.1007/s00396-021-04819-4 -
[41] Kloster 等 - 2015 - Composite films based on chitosan and nanomagnetit 10.1016/j.eurpolymj.2015.02.042 -
[42] Khan 等 - 2022 - Formulation and Characterization of Carbopol-934 B 10.3390/polym14071489 -
[43] James 等 - 2022 - Synthesis and Characterization of Novel Nano-carbo 10.15376/biores.17.3.4452-4469 -
[44] Jadhav 和 Jadhav - 2021 - Graft copolymerization of methyl methacrylate onMe 10.1007/s13726-020-00869-7 -
[45] Hickman 等 - 2021 - Influence of the tetraalkoxysilane crosslinker on 10.1039/d1py00872b -
[46] Heger 等 - 2016 - The donor OH stretching-libration dynamics of hydr 10.1039/c5cp07387a -
[47] Hassan 等 - 2021 - Hydroxypropyl Cellulose Loaded with ZnO Nanopartic 10.3390/ma13020363 -
[48] Giuliano 等 - 2010 - Infrared Spectra and Photochemistry of Matrix-Isol 10.1021/jp911118v -
[49] Ghoniem 等 - 2022 - Highly Selective Removal of Cationic Dyes from Was 10.3390/nano12061023 -
[50] Ghamry 和 Abdelmonem - 2022 - Adsorption of Co-60 and Eu154+152 Using Graft Copo 10.1007/s10924-022-02446-w -
[51] Froehlich 等 - 2013 - Libyan Desert Glass New field and Fourier transfo 10.1111/maps.12223 -
[52] Farrell 等 - 2016 - Electron donor-acceptor properties of substituted 10.1039/jr9590001501 -
[53] El-Shekeil 等 - 2012 - Effect of pMDI isocyanate additive on mechanical a 10.1177/0021998310385030 -
[54] Du 等 - 2014 - Cytotoxicity of PEGylated graphene oxide on lympho 10.3233/bme-141024 -
[55] Delgado 等 - 2019 - Ni-thiosaccharinate complexes Synthesis, characte 10.1016/j.ica.2019.04.040 -
[56] Daud 等 - 2017 - Functionalizing Graphene Oxide with Alkylamine by 10.3390/nano7060135 -
[57] Cui 等 - 2020 - Developing Further Versatility in Benzoxazine Synt 10.3390/polym12030694 -
[58] Cheng 等 - 2021 - Landfill leachate wastewater treatment to facilita 10.1016/j.chemosphere.2020.127829 -
[59] Cebotari 等 - 2018 - Caracterisation of high manganese silicides prepar 10.21741/9781945291999-9 -
[60] Baraldi 等 - 2001 - High-resolution vibrational spectroscopy of Pb-OH 10.1103/physrevb.63.134302 -
[61] Banga-Bothy 和 Samokhvalov - 2023 - Sorption and Desorption of Vapor of n-Pentane by P 10.3390/nano13091529 -
[62] Balazova 等 - 2023 - In Situ Gel with Silver Nanoparticles Prepared Usi 10.3390/life13020573 -
[63] Badr 等 - 2023 - Influence of gamma irradiation on rosin properties 10.1038/s41598-023-31372-7 -
[64] Aziz 等 - 2020 - FTIR and HPLC-Based Metabolomics of Yacon Leaves E 10.22146/ijc.43453 -
[65] Atoguchi 和 Kanougi - 2004 - Phenol oxidation over alkaline earth metal ion exc 10.1016/j.molcata.2004.08.020 -
[66] Al-Sehemi 等 - 2015 - SYNTHESIS, CHARACTERIZATION AND DENSITY FUNCTIONAL 10.4314/bcse.v29i1.13 -
[67] Akhgari 等 - 2013 - Indomethacin electrospun nanofibers for colonic dr 10.5681/apb.2013.014 -
[68] Abul-Futouh 等 - 2021 - Ligand effects on structural, protophilic and redu 10.1039/d0nj04790b -
[69] pdf20231221 cm-1 infrared 第一部分/shen 等 - 2007 - grafting of montmorillonite with different functio.pdf - -
[70] pdf20231221 cm-1 infrared 第一部分/sadjadi 等 - 2017 - a novel hybrid catalytic system based on immobiliz.pdf - -
[71] pdf20231221 cm-1 infrared 第一部分/beyazyidirim 等 - 2006 - synthesis and electrochromic properties of conduct.pdf - -
[72] 0816 ftir cm_1 peak wos/tanaka 等 - 1995 - in-situ observation of surface-oh and surface-od o.pdf - -
[73] 0816 ftir cm_1 peak wos/mathiowitz 等 - 1993 - morphological characterization of bioerodible poly.pdf - -
[74] Yuan 等 - 2016 - Synthesis of a New Titanate Coupling Agent for the 10.3390/ma9080625 -
[75] Perra 等 - 2014 - Remarkable acid strength of ammonium ions in zeoli 10.1039/c4ra12504e -
[76] Zhang 等 - 2020 - Crystal Growth of Smectite A Study Based on the C 10.1021/ac -
[77] Yun 等 - 2019 - Fabrication and characterization of conductive mic 10.1515/spma-2019-0001 -
[78] Sarelo 等 - 2020 - Antibody CD133 Biofunctionalization of Ammonium Ac 10.3390/ma13245634 -
[79] Perju 等 - 2022 - SOME ASPECTS CONCERNING TITANIUM COVERAGE WITH HYD 10.24425/amm.2022.137785 -
[80] Gupta 等 - 2022 - In vitro cell composition identification of wood d 10.1098/rsos.201935 -
[81] Gianotti 等 - 2019 - Hybrid catalysts based on N-heterocyclic carbene a 10.1039/c9ra07516j -
[82] Chavan 等 - 2013 - Fundamental Aspects of H2S Adsorption on CPO-27-Ni 10.1021/jp402440u -
[83] Cakmak-Arslan 等 - 2020 - Investigation of the Toxic Effects of Rhododendron 10.9775/kvfd.2019.22996 -
[84] Bawazeer 等 - 2021 - Green synthesis of silver nanoparticles using Trop 10.1515/gps-2021-0003 -
[85] Babic 等 - 2021 - Comparative Study of Zeolite L Etching with Ammoni 10.1002/admi.202000348 -
[86] Al-Deyab 等 - 2010 - Synthesis and Characterization of Organotin Contai 10.3390/molecules15031784 -
[87] Huang 等 - 2018 - Structural Dependence and Spectroscopic Evidence o 10.1021/acs.jpcb.8b03178 -
[88] Young 和 McDonald - 2021 - Preparation and Characterization of Biobased Ligni 10.3390/molecules26092437 -
[89] Kert 等 - 2021 - Application of Fragrance Microcapsules onto Cotton 10.3390/coatings11101181 13
[90] Arjunan 等 - 2012 - Quantum chemical studies and vibrational analysis 10.1016/j.saa.2012.08.053 12
[91] Arivazhagan 和 Rexalin - 2013 - Vibrational spectra, UV-vis spectral analysis and 10.1016/j.saa.2013.01.029 4
[92] Al-Sehemi 等 - 2015 - SYNTHESIS, CHARACTERIZATION AND DENSITY FUNCTIONAL 10.4314/bcse.v29i1.13 1
[93] Nilsuwan 等 - 2016 - Influence of palm oil and glycerol on properties o 10.1007/s13197-016-2243-7 8
[94] Rizzuto 等 - 2022 - Plasticizers and Salt Concentrations Effects on Po 10.3390/gels8060363 9
[95] Mohamed 等 - 2020 - Conservation and Characterization of Arabic Papyru 10.1088/1757-899X/949/1/012003 7
[96] Tyubaeva 等 - 2023 - Development of Nonwoven Fibrous Materials Based on 10.3390/polym15153167 7
Appendix

Sample information and raw spectrum

Original uploaded spectrum for reference and verification.

Baseline correction method: Asymmetric Least Squares Smoothing

The wavelength range for analysis(cm-1): N/A

Raw spectrum without baseline correction or other processing:

Sample spectrum image
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