{"id":8,"date":"2012-10-19T13:34:49","date_gmt":"2012-10-19T12:34:49","guid":{"rendered":"http:\/\/scr-mi.insa-rennes.fr\/guillaumecalvez\/?page_id=7"},"modified":"2026-01-14T11:13:27","modified_gmt":"2026-01-14T10:13:27","slug":"research","status":"publish","type":"page","link":"https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/research\/","title":{"rendered":"Research"},"content":{"rendered":"<table style=\"width: 100%; height: 142px;\" border=\"0\" cellspacing=\"0\" cellpadding=\"5px\" align=\"center\">\n<tbody>\n<tr style=\"height: 86px;\">\n<td style=\"height: 86px;\">\u00a0<a title=\"Guillaume Calvez\" href=\"https:\/\/www.researchgate.net\/profile\/Guillaume_Calvez\/\" target=\"_blank\" rel=\"noopener\"><img decoding=\"async\" src=\"https:\/\/www.researchgate.net\/images\/public\/profile_share_badge.png\" alt=\"Guillaume Calvez\" \/>\u00a0\u00a0\u00a0\u00a0<\/a><a href=\"https:\/\/cv.hal.science\/guillaumecalvez\/\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-385 alignnone\" src=\"https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-content\/uploads\/sites\/9\/2018\/06\/logo_hal_tampon_RVB-300x300.jpg\" alt=\"\" width=\"78\" height=\"78\" srcset=\"https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-content\/uploads\/sites\/9\/2018\/06\/logo_hal_tampon_RVB-300x300.jpg 300w, https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-content\/uploads\/sites\/9\/2018\/06\/logo_hal_tampon_RVB-150x150.jpg 150w, https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-content\/uploads\/sites\/9\/2018\/06\/logo_hal_tampon_RVB.jpg 671w\" sizes=\"auto, (max-width: 78px) 100vw, 78px\" \/><\/a><\/td>\n<\/tr>\n<tr style=\"height: 28px;\">\n<td style=\"height: 28px;\"><a href=\"http:\/\/orcid.org\/0000-0002-2133-7214\" target=\"_blank\" rel=\"noopener\">ORCID<\/a>\u00a0 \u00a0 <a href=\"http:\/\/www.scopus.com\/authid\/detail.url?authorId=23468743700\" target=\"_blank\" rel=\"noopener\">Scopus<\/a>\u00a0\u00a0\u00a0 <a href=\"https:\/\/scholar.google.fr\/citations?user=kCPpNeQAAAAJ\" target=\"_blank\" rel=\"noopener\">Google Scholar<\/a>\u00a0 \u00a0 <a href=\"https:\/\/www.zotero.org\/gcalvez\" target=\"_blank\" rel=\"noopener noreferrer\">Zotero<\/a>\u00a0 \u00a0 <a href=\"https:\/\/www.idref.fr\/139456899\" target=\"_blank\" rel=\"noopener\">IdRef<\/a><\/td>\n<\/tr>\n<tr style=\"height: 28px;\">\n<td style=\"height: 28px;\"><a title=\"Publications HAL\" href=\"https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/publications\/\">Scientific publications<\/a><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"text-decoration: underline;\"><strong>Main topics:<\/strong><\/span> <strong>Lanthanide Coordination Chemistry \/ Hexanuclear Complexes \/ Luminescence UV, vis.<\/strong><strong>, IR &amp; Qy measurement<\/strong><\/p>\n<hr \/>\n<p>Filed patent application \u2013 n\u00b01258525, France (September, 11th 2012)<br \/>\nFR2995316-A1 (2014-03-14) WO2014040917-A1 (2014-03-20)<br \/>\nPROCESS FOR MARKING AT LEAST ONE MATERIAL COMPRISING A SOLID OR LIQUID, ORGANIC OR MINERAL MATRIX, AND SAID CORRESPONDING MATERIAL<\/p>\n<hr \/>\n<p><span style=\"text-decoration: underline;\"><em>Hexanuclear complexes<\/em><\/span><\/p>\n<p><a href=\"https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-content\/uploads\/sites\/9\/2012\/10\/hexaY1.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-191\" src=\"https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-content\/uploads\/sites\/9\/2012\/10\/hexaY1-300x240.png\" alt=\"hexaY1\" width=\"270\" height=\"216\" srcset=\"https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-content\/uploads\/sites\/9\/2012\/10\/hexaY1-300x240.png 300w, https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-content\/uploads\/sites\/9\/2012\/10\/hexaY1-1024x819.png 1024w, https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-content\/uploads\/sites\/9\/2012\/10\/hexaY1-375x300.png 375w, https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-content\/uploads\/sites\/9\/2012\/10\/hexaY1.png 1280w\" sizes=\"auto, (max-width: 270px) 100vw, 270px\" \/><\/a>\u00a0\u00a0<a href=\"https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-content\/uploads\/sites\/9\/2012\/10\/hexaY2.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-191\" src=\"https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-content\/uploads\/sites\/9\/2012\/10\/hexaY2-300x240.png\" alt=\"hexaY2\" width=\"270\" height=\"216\" \/><\/a><\/p>\n<p>Hexanuclear lanthanide complex [Ln<sub>6<\/sub>(\u00b5<sub>6<\/sub>-O)(\u00b5<sub>3<\/sub>-OH)<sub>8<\/sub>(NO<sub>3<\/sub>)<sub>6<\/sub>(H<sub>2<\/sub>O)<sub>12<\/sub>]<sup>2+<\/sup> with Ln = Pr-Lu, Y<\/p>\n<p>Using this compound <a title=\"Calvez, G.; Daiguebonne, C.; Guillou, O.; Pott, T.; M\u00e9l\u00e9ard, P.; Le Dret, F., Lanthanide-Based Hexanuclear Complexes Usable as Molecular Precursor for New hybrid Materials. C.R.Chim. 2010, 13 (6-7), 715-730\" href=\"http:\/\/dx.doi.org\/10.1016\/j.crci.2010.03.029\" target=\"_blank\" rel=\"noopener noreferrer\">as starting reagent<\/a> we have obtained strongly luminescent coordination polymers (that we cannot obtain from simple salts)<\/p>\n<p>The aim of this project is to obtain coordination polymers where polynuclear complexes would act as metallic centers _________________________________________________________________________<\/p>\n<p><span style=\"text-decoration: underline;\"><em>Luminescence<\/em><\/span><\/p>\n<p>We study the\u00a0<a href=\"..\/..\/?page_id=13\" target=\"_blank\" rel=\"noopener noreferrer\">luminescent properties<\/a>\u00a0of coordination polymers to:<\/p>\n<ul>\n<li>enhance the emitted light (for potential use as luminophores or phosphors)<\/li>\n<li>enhance the quantum yield Qy (which is quite different from the first point because their UV absorption varies greatly depending on the ligand being used)<\/li>\n<li>fine-tune the emitted color and excitation wavelength (playing on ligands and composition)<\/li>\n<\/ul>\n<p><em>For instance:<\/em><\/p>\n<p>These spectra correspond to two compounds, in dark green the starting complex and in light green the same complex functionalized so as to enhance its luminescence.<\/p>\n<p><a href=\"https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-content\/uploads\/sites\/9\/2012\/10\/lumTb.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-196\" src=\"https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-content\/uploads\/sites\/9\/2012\/10\/lumTb-300x182.png\" alt=\"lumTb\" width=\"300\" height=\"182\" srcset=\"https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-content\/uploads\/sites\/9\/2012\/10\/lumTb-300x182.png 300w, https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-content\/uploads\/sites\/9\/2012\/10\/lumTb-493x300.png 493w, https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-content\/uploads\/sites\/9\/2012\/10\/lumTb.png 863w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>The excitation spectra are quite different: the functionalized compound shows a huge excitation band which rise above 300nm. This absorption band is due to the ligand being used (a benzene-polycarboxylate) which is able to transfer photons to the lanthanide and thus enhances its emissive properties. This well-known phenomena is called <code>\"<\/code>antenna effect<code>\"<\/code>. _________________________________________________________________________<\/p>\n<p><span style=\"text-decoration: underline;\"><em>Quantum yield measurement<\/em><\/span><\/p>\n<p>The Qy value gives the number of photons emitted by a sample divided by the number of photons absorbed by this same sample. We measure it in an integration sphere with a <a title=\"facilities\" href=\"http:\/\/www.insa-rennes.fr\/iscr-csm\/equipements\" target=\"_blank\" rel=\"noopener noreferrer\">spectrophotometer<\/a>.<\/p>\n<p>We are often surprised by Qy values, because it is not an absolute measurement of the light emitted by the sample: the number of emitted photons is divided by the number of <strong>absorbed<\/strong> photons, not by that of the <strong>received<\/strong> ones. So, some compounds with a weak UV\u00a0absorption\u00a0may present a weak light emission but a high quantum yield.<\/p>\n<p>In order to evaluate the absolute light emission properties of a luminophore, we use a <strong>fluxmeter<\/strong> to measure the UV light received on the surface (irradiance: W\/cm\u00b2) and a <strong>lumenmeter<\/strong> to measure the visible light emitted by the surface (luminance: cd\/cm\u00b2). After conversion of candelas in lumens (related to the 3D geometry of the measurement), the ratio of lm\/W (<em>i.e.<\/em> <strong>luminous efficacy<\/strong>) can be compared with every other light emitting device (for example a commercial source of light).<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u00a0\u00a0\u00a0\u00a0\u00a0 ORCID\u00a0 \u00a0 Scopus\u00a0\u00a0\u00a0 Google Scholar\u00a0 \u00a0 Zotero\u00a0 \u00a0 IdRef Scientific publications Main topics: Lanthanide Coordination Chemistry \/ Hexanuclear Complexes \/ Luminescence UV, vis., IR &amp; Qy measurement Filed patent application \u2013 n\u00b01258525, France (September, &hellip; <a href=\"https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/research\/\" class=\"more-link\">Lire la suite <span class=\"screen-reader-text\">Research<\/span> <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-8","page","type-page","status-publish","hentry"],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-json\/wp\/v2\/pages\/8","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-json\/wp\/v2\/comments?post=8"}],"version-history":[{"count":27,"href":"https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-json\/wp\/v2\/pages\/8\/revisions"}],"predecessor-version":[{"id":513,"href":"https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-json\/wp\/v2\/pages\/8\/revisions\/513"}],"wp:attachment":[{"href":"https:\/\/iscr-csm.insa-rennes.fr\/guillaumecalvez\/wp-json\/wp\/v2\/media?parent=8"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}