What absorbs at 775 cm⁻¹ in an FTIR spectrum?

Быстрый ответ

A band near 775 cm⁻¹ is usually interpreted by checking which functional groups repeatedly co-occur there in the literature, then confirming at least one or two additional peaks in the same sample. This page ranks those assignments by accumulated evidence rather than by a single fixed textbook rule.

Возможные назначения функциональных групп

Ранжирование отражает накопленные литературные данные, а не единственное авторитетное правило. Всегда проверяйте в контексте вашего образца.

Возможные материалы

Материалы отображаются только при поддержке данной полосы и хотя бы одного дополнительного характеристического пика из того же литературного пула.

Логика спектра

This band becomes meaningful only when read with its neighboring peaks. In practice, analysts first look at the assignments above, then check whether the same sample also shows other peaks expected for the same structural motif. A lone band near 775 cm⁻¹ is usually not enough for material identification by itself.

Использование в реальных условиях

Такой тип запроса распространен при идентификации полимеров, скрининге неизвестных пластиков, устранении неполадок в контроле качества, проверке переработанных материалов и анализе отнесения пиков на основе литературы.

Распространенные ошибки

• Рассмотрение одной изолированной полосы как доказательства материала без проверки хотя бы одного или двух поддерживающих пиков.
• Игнорирование перекрытия: несколько функциональных групп могут вносить вклад вблизи одного и того же волнового числа.
• Пропуск проверки, когда добавки, смеси, окисление или загрязнение могут исказить спектр.

Рекомендации по проверке

Когда остается неоднозначность, проверьте гипотезу с помощью DSC, GC-MS или TGA, особенно для смесей, деградированных образцов и наполненных полимеров.

Литература, лежащая в основе этих назначений

• Acetate достоверность 1,0

  “TC-DO at 1412 and 779 W-DM had characteristic peaks at 1723 (C=O vibration), 1514, cm-1 corresponding to the characteristic peaks of TC-DM at 1643, 1465, 1413, 1456, 1422 and 775 cm-1.”

  Discrimination and similarity evaluation of tissue-cultured and wild Dendrobium species using Fourier Transform Infrared Spectroscopy DOI: 10.1016/j.molstruc.2015.01.027
• достоверность 1,0

  “6 FTIR spectra for a b c and of SPEs 16:2251-2260 2258 J Solid State Electrochem (2012) cm-1 8.0×10-8 cm-1 C-Cl functional group of stretching at 775 for aliphatS is obtained at 15% wt.”

  Lee 等 - 2012 - Temperature dependence of the conductivity of plas DOI: 10.1007/s10008-011-1633-z
• Phosphate (PO4) достоверность 1,0

  “In the metaphosphate 775cm-1, (P-O-P) and (P-O-P) bands at about 900 and glass composition, CuO primarily acts as network modias s 43Q2 groups respectively, and the deformation modes of PO fier to depolymerize phosphate chain, until all the”

  Shih 等 - 2003 - P-31 MAS-NMR and FTIR analyses on the structure of DOI: 10.1016/S0254-0584(03)00098-1
• Alkene (C=C) достоверность 1,0

  “1624 Strong (methyne) 775 Medium Alkenyl C=C stretch Olefinic alkene 1458 Medium C=C-C aromatic ring stretch 775 Medium Alkenyl C=C stretch”

  The Antimicrobial Activities of Silver Nanoparticles from Aqueous Extract of Grape Seeds against Pathogenic Bacteria and Fungi DOI: 10.3390/molecules26196081
• Amide достоверность 1,0

  “The third (1239 and fourth cm-1) (775 amide band can be clearly seen only for PSi0, because in the PSi samples those bands are overlapped by the stronger aforementioned bands”

  Thermal and surface properties of hybrid materials obtained from epoxy-functional urethane and siloxane DOI: 10.1007/s00289-015-1545-7
• Acetate достоверность 1,0

  “(C-H 3308 stretching vibration), 2933 stretching of CH2 group), recorded in native nanocomposite components, were assigned corre- - O-H C-H 1602 (COOH stretching), 1429 (uronic acid (COOH)), 1018 825 sponding to stretching vibration at 3292”

  Green decoration of graphene oxide Nano sheets with gelatin and gum Arabic for targeted delivery of doxorubicin DOI: 10.1016/j.btre.2022.e00722
• Amide достоверность 1,0

  “a major peak has appeared at 775 These peaks were characteristic of C-N stretch (amines), =C-H bend (benzene, alkenes), and C-C (chlorides).”

  Potential of Suaeda nudiflora and Suaeda fruticosa to Adapt to High Salinity Conditions DOI: 10.3390/horticulturae9010074
• Thiocarbonyl достоверность 1,0

  “The following inference are made from the Cd2+, concentration of free as much of these ions would be in cm-1 found for pure observed FTIR results,The band at 775 42complex and most of the allylthiourea the form of CdCl Allylthiourea is assi”

  Perumal 等 - 2023 - Influence of pH on the Growth of Tris-Allylthioure DOI: 10.14447/jnmes.v26i2.a07