{"id":46,"date":"2023-11-04T20:13:34","date_gmt":"2023-11-04T20:13:34","guid":{"rendered":"https:\/\/www-cxcp1.tifrh.res.in\/~vipin\/?page_id=46"},"modified":"2024-08-06T16:30:47","modified_gmt":"2024-08-06T16:30:47","slug":"heteronuclear-decoupling","status":"publish","type":"page","link":"https:\/\/www.tifrh.res.in\/~vipin\/heteronuclear-decoupling\/","title":{"rendered":"Heteronuclear decoupling"},"content":{"rendered":"

[et_pb_section fb_built=”1″ _builder_version=”4.23″ _module_preset=”default” custom_padding=”5px|||||” global_colors_info=”{}”][et_pb_row _builder_version=”4.23″ _module_preset=”default” border_width_bottom=”1px” border_color_bottom=”#e2e2e2″ global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.23″ _module_preset=”default” global_colors_info=”{}”][et_pb_post_title meta=”off” featured_image=”off” _builder_version=”4.23″ _module_preset=”default” global_colors_info=”{}”][\/et_pb_post_title][\/et_pb_column][\/et_pb_row][et_pb_row use_custom_gutter=”on” gutter_width=”2″ _builder_version=”4.23″ _module_preset=”default” global_colors_info=”{}”][et_pb_column type=”4_4″ _builder_version=”4.23″ _module_preset=”default” global_colors_info=”{}”][et_pb_text _builder_version=”4.23″ _module_preset=”default” custom_padding=”0px|||||” global_colors_info=”{}”]<\/p>\n

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Optimization independent heteronuclear decoupling at fast MAS<\/h4>\n

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Heteronuclear decoupling is important\u00a0to maximize\u00a0resolution and improve sensitivity. Several decoupling sequences such as TPPM, SWf<\/sub>-TPPM, SPINAL, XiX, AM-XiX and PISSARRO perform reasonably well but require careful experimental optimisation\u00a0of at least one or more parameters.\u00a0<\/span>However, the optimised\u00a0parameters are sensitive to experimental parameters.\u00a0<\/span>For samples with relatively high signal to noise, this is not an issue, and decoupling conditions can be\u00a0 re-optimised. However, samples with poor signal to noise are standard in solid-state and in such cases, optimisation\u00a0of each parameter is demanding. Therefore, there was a need for heteronuclear sequences that are practically optimization independent, especially in the fast MAS regime where detection of 13<\/sup>C and 15<\/sup>N signals is very insensitive.<\/p>\n

In the fast MAS regime (40 kHz and above), we have designed two low-power heteronuclear decoupling sequences that are practically optimization independent. The two new heteronuclear decoupling sequences are a) low-power rCWApA<\/sup>and b) the refocused-XiX (r-XiX). The knowledge of the MAS frequency and approximate RF fields is sufficient to predict the necessary parameters for decoupling.<\/p>\n<\/div>\n

[\/et_pb_text][et_pb_image src=”https:\/\/www.tifrh.res.in\/~vipin\/wp-content\/uploads\/2024\/08\/Untitled2.png” title_text=”Untitled2″ _builder_version=”4.23″ _module_preset=”default” global_colors_info=”{}”][\/et_pb_image][et_pb_text _builder_version=”4.23″ _module_preset=”default” global_colors_info=”{}”]<\/p>\n

Figure: decoupling performance of optimization independent sequences rCWApA<\/sup><\/em>\u00a0and r-XiX\u00a0<\/em>with other sequence at 60kHz MAS and 10 kHz proton amplitude<\/p>\n

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Relevant Publications<\/h5>\n
    \n
  • Asif Equbal, P.K.Madhu, Beat H. Meier, Niels C. Nielsen, Matthias Ernst and Vipin Agarwal Parameter independent low-power decoupling for Fast Magic-Angle Spinning in Solid-State NMR.<\/em>\u00a0J. Chem. Phys. (2017)<\/li>\n
  • Mukul G. Jain, K.N. Sreedevi, Asif Equbal, P.K. Madhu and Vipin Agarwal,Refocusing pulses: A strategy to improve efficiency of phase-modulated heteronuclear decoupling schemes in MAS solid-state NMR\u00a0<\/em>\u00a0J. Magn. Reson., 284, 59-65 (2017)<\/em><\/li>\n
  • Kong Ooi Tan, Vipin Agarwal, Beat H. Meier and Matthias Ernst, A Generalized Theoretical Framework for the Description of Spin Decoupling\u00a0in Solid-State MAS NMR: Properties of Low-Power Experiments. J. Chem. Phys., 145, 094201 <\/em>(2016)<\/li>\n
  • Kshama Sharma, P.K.Madhu and Vipin Agarwal,<\/u>Systematic evaluation of heteronuclear decoupling at rotary resonance conditions in the regime of fast MAS <\/em> Magn. Reson., 270, 136-141<\/em> (2016)<\/li>\n
  • Vipin Agarwal, Tiit Tuherm, Andres Reinhold, Jaan Past, Ago Samoson, Matthias Ernst and Beat H. Meier. Amplitude modulated low-power decoupling sequences for Fast Magic-Angle Spinning NMR. <\/em>Chem.\u00a0Phys. Lett. 583, 1-7 (2013)<\/li>\n<\/ul>\n

    [\/et_pb_text][\/et_pb_column][\/et_pb_row][\/et_pb_section]<\/p>\n","protected":false},"excerpt":{"rendered":"

    Optimization independent heteronuclear decoupling at fast MAS   Heteronuclear decoupling is important\u00a0to maximize\u00a0resolution and improve sensitivity. Several decoupling sequences such as TPPM, SWf-TPPM, SPINAL, XiX, AM-XiX and PISSARRO perform reasonably well but require careful experimental optimisation\u00a0of at least one or more parameters.\u00a0However, the optimised\u00a0parameters are sensitive to experimental parameters.\u00a0For samples with relatively high signal to […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_et_pb_use_builder":"on","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"class_list":["post-46","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.tifrh.res.in\/~vipin\/wp-json\/wp\/v2\/pages\/46"}],"collection":[{"href":"https:\/\/www.tifrh.res.in\/~vipin\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.tifrh.res.in\/~vipin\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.tifrh.res.in\/~vipin\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.tifrh.res.in\/~vipin\/wp-json\/wp\/v2\/comments?post=46"}],"version-history":[{"count":5,"href":"https:\/\/www.tifrh.res.in\/~vipin\/wp-json\/wp\/v2\/pages\/46\/revisions"}],"predecessor-version":[{"id":140,"href":"https:\/\/www.tifrh.res.in\/~vipin\/wp-json\/wp\/v2\/pages\/46\/revisions\/140"}],"wp:attachment":[{"href":"https:\/\/www.tifrh.res.in\/~vipin\/wp-json\/wp\/v2\/media?parent=46"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}