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A new bismuth molybdate, obtained by means of microwave-assisted hydrothermal synthesis, is described by the chemical formula: β(L)-Bi2Mo2O9, in accordance with its low crystallization temperature and transition to β-Bi2Mo2O9 at 532 °C. Its structure, solved ab initio using powder diffraction data, crystallizes in the monoclinic system (space group P21/c), with a = 8.11413(5), b = 8.54445(5), c = 13.43623(6) A, and β = 123.5085(2)°. This phase has been tested as a catalyst for the oxidation of propene. It appears to be highly stable on stream, with a specific rate of propene conversion comparable to that of α-Bi2Mo3O12 and a slightly higher selectivity to acrolein. A possible active site for the abstraction of the first hydrogen from propene has been identified, by analogy with that proposed for α-Bi2Mo3O12 and seems to correspond to a molybdenyl Mo = O oxygen that is weakly coordinated to a neighboring Bi cation.

SSCI-VIDE+CDFA+OVE:SVD:ADM; International audience; Phase changing coordination polymers have been proposed to have potential application in the area of memory storage (Phase-Change Random Access Memory (PCRAM)). Phase change in porous coordination polymers (PCPs) largely depends on the guest-host chemistry and these changes are mostly reversible. Whereas due to dense packing in non-porous coordination polymers, achieving phase change is quite challenging. In 2015, Prof. Demessence and co-workers reported phase-change in Au(I) based [Au(SPh)]n coordination polymer (CP) through simply calcinating the amorphous phase. It is one of the rare example where thermal polymorpharization of the CP could be achieved. In this poster we present systematic thermal polymorpharization of [Au(SEtPh)]n CP. These polymorphs have different structures and hence have different photo-physical properties.

SSCI-VIDE+CDFA+OVE:ADM; International audience; Thiosalicylic acid is hard-soft donor ligand, able to coordinate numerous metals [1]. A significant number of coordination compounds of d10 metals have been reported. However, crystallographic studies of polymeric species stayed very limited compared to their mono- and oligomeric counterparts. For example, preparation of polymeric [Au(oSCPhCO2H)]n has been reported [2], as well as polymeric compounds of silver thiosalicylate [3], but no crystallographic structure was reported. A number of Cu(II) thiosalicylates [4], a mixed-valence Cu(I)2Cu(II) complex [5] and no Cu(I) complexes have been described up to our knowledge. In most cases structural studies are precluded due to the strong affinity between sulfur and coinage metals, inducing a rapid precipitation of coordination polymers making single crystals hardly obtainable. In presented work, we report extensive pioneering structural study of three polymeric species of Cu(I), Au(I) and Ag(I). Structural study was performed by means of powder X-ray diffraction and PDF (pair distribution function) calculations. These coordination polymers have similar 1D structures. Based on this fact, we are able to discuss the influence of the structure and the nature of the metallic ion on photophysical properties of these materials. They emin in orange to NIR part of the spectrum. High quantum yields make them interesting for illumination and as NIR-emitters. [1] T. Wehr-Candler et al. Coord. Chem. Rev. 2016, 313, 111.[2] R.E. Bachman et al. Z. Naturforsch. 2009, 64B, 1491. [3] K. Nomiya et al. J. Inorg. Biochem. 1995, 58, 255. [4] See for example M.S. Abu-Bakr, Monatsh. Chem. 1997, 128, 563. [5] R.C. Bott et al. Chem. Commun. 1998, 2403.

SSCI-VIDE+CDFA+OVE:ADM; International audience; Hybrid materials with chalcogenate ligands (-ER = SR, SeR, TeR) and d10 coinage metals (M(I) = Cu, Ag and Au) are known for a long time mainly in the domains of biology and pharmaceutics.1 Indeed, copper-thiolates are present in most of the living organisms as metalloproteins, silver-thiolates are recognized for their anti-bacterial activity and some gold-thiolates, as the Myochrysine, have been used as antiarthritic drugs. Today, the d10 coinage Metal Organic Chalcogenates (MOCs) are gaining a growing relevance in materials science for their semiconductivity and photoluminescence properties. Indeed, the photoemission of these compounds is attributed to the presence of d10 coinage metals and their ability to display metallophilic interactions. Neutral MOCs, defined with the formula [M(ER)]n, can form cyclic oligomers and extended coordination polymers with 1D or 2D structures as a limited number. In this presentation we will show the variety of the chain-like and lamellar structures of these MOCs, associated to a rich palette of photophysical properties. Thus, some compounds exhibit high quantum yield (~70 %) in the solid state and some have an intrinsic triple emission associated with luminescence thermochromism allowing optical temperature sensing. This study will show the great potential of the MOCs as phosphorescent hybrid materials and their great potential in electronic devices, sensors or photocatalysis.1. Veselska, O.; Demessence, A., Coord. Chem. Rev. 2018, 355, 240.

SSCI-VIDE+CDFA+OVE:ADM; International audience; Hybrid Au(I) compounds exhibit a large domain of applications such as electronic devices, contrast agents, sensors or photocatalysts and are well known for their diverse photophysical properties, often implied by the aurophilic interactions1. Among them, gold(I) thiolates are an important class of materials, due to the strong soft-soft interaction between Au(I) and thiolates, and their potential to form self-assembled monolayers, functionalized nanoparticles and coordination oligomers or polymers. However, despite their great interest, the neutral Au(I)-thiolate coordination polymers remain underinvestigated. Thus, a little is known about their structure2 and the origin of their photophysical properties.Here, we report the first structures of coordination polymers of gold(I) and ortho-, meta-, para mercaptobenzoic acids. We will show how change of the position of substituent influences the structure formation giving 1D or 2D extended networks. Hence, each of these compounds exhibit distinct photophysical properties such as thermoluminochromism, thermally activated delayed fluorescence (TADF) or high quantum yield (Fig. 1), pointing out the high potential of gold-thiolate coordination polymers as temperature sensing or optoelectronic devices.31. H. Schmidbaur, A. Schier, Chem. Soc. Rev., 2012, 41, 370.2. O. Veselska, A. Demessence, Coord. Chem. Rev., 2018, 355, 240.3. O. Veselska, L. Okhrimenko, N. Guillou, D. Podbevšek, G. Ledoux, C. Dujardin, M. Monge, D. Chevrier, R. Yang, P. Zhang, A. Fateeva, A. Demessence, J. Mater. Chem. C., 2017, 5, 9843.

SSCI-VIDE+CDFA+OVE:ADM; International audience; Hybrid Au(I) compounds exhibit a large domain of applications such as electronic devices, contrast agents, sensors or photocatalysts. These applications are related to the ability of gold(I) to form aurophilic interactions implying self-assembly and luminescence.1 Among them, gold(I) thiolates are an important class of materials, due to the soft-soft interaction between Au(I) and thiolates, and their potential to form self-assembled monolayers, to protect and functionalize gold clusters and nanoparticles and to generate oligomeric or polymeric species, used for a long time as antiarthritic agents. However due to the fast precipitation and the insolubility of these solids, a little is known about their structure making the origin of the photoluminescence difficult to rationalized.2 Here, we present the syntheses and the first structure resolutions, by powder X-Ray diffraction, of series of gold(I)-thiophenolate-based coordination polymers, [Au(SPhR)]n. Depending on the substituent and its position, different chain-like and lamellar structures are obtained.3 The photophysical properties of these hybrid materials are analyzed in solid-state and coupled with DFT calculations. These studies show different origins of the charge transfers depending on the electrophilicity of the thiolate molecules coupled with the participation or not of the aurophilic interactions. Among those coordination polymers, some exhibit high quantum yield around 70 % at room temperature and in the solid state,3b another one shows an rare switch ON of the emission with a thermally induced solid-state phase change from amorphous to crystalline.3a When the mercaptobenzoic acids are used in ortho and para positions, the structures of the resulting [Au(SPhCO2H)]n coordination polymers are 1D and 2D, respectively. Thus their photoluminescent properties are distinct, [Au(o-SPhCO2H)]n presents thermally induced delayed fluorescence (TADF) phenomenon and in the case of the [Au(p-SPhCO2H)]n, its dual emission, associated with luminescence thermochromism was highlighted as intrinsic and ratiometric optical temperature sensor.3c These different examples shed light on the great potential of gold thiolate coordination polymers as emerging hybrid materials for diverse optical applications. References[1].H. Schmidbaur; A. Schier, Chem. Soc. Rev., 2012, 41, 370.[2].O. Veselska; A. Demessence, Coord. Chem. Rev., 2018, 355, 240.[3].(a) C. Lavenn; L. Okhrimenko; N. Guillou; M. Monge; G. Ledoux; C. Dujardin; R. Chiriac; A. Fateeva; A. Demessence, J. Mater Chem. C, 2015, 3, 4115; (b) C. Lavenn; N. Guillou; M. Monge; D. Podbevšek; G. Ledoux; A. Fateeva; A. Demessence, Chem. Commun., 2016, 52, 9063; (c) O. Veselska; L. Okhrimenko; N. Guillou; D. Podbevsek; G. Ledoux; C. Dujardin; M. Monge; D. M. Chevrier; R. Yang; P. Zhang; A. Fateeva; A. Demessence, J. Mater Chem. C, 2017, 5, 9843.

SSCI-VIDE+CDFA+ADM:OVE; International audience; Hybrid Au(I) compounds exhibit a large domain of applications such as electronic devices, contrast agents, sensors or photocatalysts. These applications are related to the ability of gold(I) to form aurophilic interactions implying self-assembly and luminescence.1 Among them, gold(I) thiolates are an important class of materials due to the high affinity of gold for sulfur atoms that can generate oligomers or polymers. However due to the fast precipitation and the insolubility of these solids, a little is known about their structure and the origin of the photoluminescence. We present the syntheses and the first structure resolutions, by powder X-Ray diffraction, of series of gold(I)-thiophenolate-based compounds. Depending on the substituent different structures are obtained: lamellar, helicoidal or cyclic (Fig. 1a). The photophysical properties of these hybrid materials are studied in solid-state and coupled with DFT calculations. These analyses show that the charge transfer from Ligand-to-Metal or Metal-to-Ligand and the quantum yield from few percentage to 70 %, can be tuned with the electrophilicity of the thiolates.2-3 Among those coordination polymers, two exhibit dynamic OFF/ON emission switching, one associated with a thermally induced solid-state phase change from amorphous to crystalline2 and the other one from a reversible esterification/saponification. Finally we synthesized luminescent, crystalline and flexible fibers of [Au(SPh)]n and generated by calcination composite materials mixing gold nanoparticles (GNP) and fibers (Fig. 1b and c). This study shows the great potential of gold thiolates as phosphorescent hybrid materials and as precursors for the formation of multifunctional nanocomposites coupling plasmonic and luminescence in electronic devices or photocatalysis.

SSCI-VIDE+CDFA+OVE:ADM; National audience; Hybrid Au(I) compounds exhibit a large domain of applications such as electronic devices,contrast agents, sensors or photocatalysts. These applications are related to the ability of gold(I) to form aurophilic interactions implying luminescence.[1] Among them, gold(I) thiolates are an important class of materials, that can generate oligomeric or polymeric structures due to the high affinity of gold for sulfur atoms. This also implies a high reactivity between thiols gold precursor and the formation of insoluble products. Thus, a little is known about their structure and the origin of the photophysical properties. Only three crystallographic structures of gold(I) thiolates coordination polymers have been reported: two having double interpenetrated helical chains[2] and one having a lamellar structure.[3] Among them two exhibit red photo-emission with extreme quantum yields of around 5 and 70 % in solid state at room temperature. Thus, a little is known about the origin of the photoluminescence of gold thiolate coordination polymers and the relation with the structure and the effect of the ligands. Here we present syntheses and structure resolutions by powder X-Ray diffraction of three new Au(I)-thiophenolate-based lamellar compounds: [Au(oSPhNH2)]n, [Au(pSPhCOOH)]n and [Au(mSPhCOOH)]n. The first one, amino function, forms double interpenetrated helicalchains, as already reported [Au(SPh)]n,[2] but is emissive in the near infra-red. The two other compounds with carboxylic acids in para and meta position have lamellar structures with a quite similar helical and parallel Au(I)-S chains (Fig. 1). Nevertheless, aurophilic distances between the chains are a bit different. Thus, despite the structures are quite similar, the photophysical properties are different. [Au(mSPhCOOH)]n exhibits only one emission peak centered at 600 nm that originates from Ligand-to-Metal-to-Ligand Charge Transfer, meanwhile [Au(pSPhCOOH)]n shows dual emission with peaks at 495 and 650nm that originate from Ligand Charge Transfer and Ligand-to-Metal-to-Metal Charge Transfer respectively.The study shows for the first time the sensitivity and richness of structures and photophysicalproperties of gold thiolate coordination polymers. With this high tunability we valorize these materials as either lighting applications or as an optical thermometer with the thermochromic solid.References1. H. Schmidbaur, A. Schier, Chem. Soc. Rev., 2012, 41, 370-412.2. C. Lavenn, L. Okhrimenko, N. Guillou, M. Monge, G. Ledoux, C. Dujardin, R. Chiriac, A. Fateeva, A. Demessence, J. Mater. Chem. C, 2015, 3, 4115-4125.3. C. Lavenn, N. Guillou, M. Monge, D. Podbevšek, G. Ledoux, A. Fateeva, A. Demessence, Chem. Commun., 2016, 52, 9063-9066.

SSCI-VIDE+CDFA+OVE:ADM; National audience; Metal thiolate compounds represent a large family of materials including nanoparticles, self-assembled monolayers and oligomeric/polymeric species showing diverse properties and applications. Among them [M(I)(SR)]n coordination polymers have been studied for a long time, for example hybrid Au(I) compounds have been used as anti arthritic drugs; Ag(I) compounds are known for their antibacterial properties[1] and Cu(I) compounds were recently shown to be good electrical conductors.[2] Moreover, these materials present great interest due to their ability to form metalophilic interactions which often imply luminescence.[3] However, despite interesting properties and potential applications, little is known about their structures. Indeed, the high affinity of M(I) for sulfur atoms implies a high reactivity between thiols and metal precursors and the formation of insoluble products.Metal thiolate phases, when the metal is Cu, Ag and Au, described in the literature can be classified according to the dimensionality of the -M(I)-S- motive into 0D, 1D and 2D-structures. The lamellar compounds are well-known, but only three structures are reported: [Au(pSPhCO2CH3)]n, [Ag(othiopyridine)]n, [Cu(pSPhOH)]n. The structure of [Au(pSPhCO2CH3)]n has been recently solved by powder X-Ray diffraction and exhibits an ultra-bright luminescence with a quantum yield over 70 % at room temperature in solid state.[4] From this result, we extended this study to other lamellar M(I)-thiophenolate coordination polymers. We will present the syntheses and structure resolutions by powder and single crystal X-Ray diffraction of series of 5 new M(I)-thiophenolate-based compounds [M(I)(pSPhCO2X)]n (M = Au, Ag, Cu and X = H and CH3). We will show how the presence of weak interactions can impact the structure and photophysical properties. In addition, some of these compounds show thermochromism with intrinsic dual emission. So, we will discuss their high potential as optical ratiometric thermometers exhibiting some of the best sensitivity parameters exceeding the performances of the lanthanide-based hybrid coordination polymers.References:[1] B. O. Leung, F. Jalilehvand, V. Mah, M. Parvez, Q. Wu, Inorg. Chem. 2013, 52, 4593-4602.[2] H. Yan, J. N. Hohman, F. H. Li, C. Jia, D. Solis-Ibarra, B. Wu, J. E. P. Dahl, R. M. K. Carlson, B. A. Tkachenko, A. A. Fokin, Nature materials, 2016.[3] H. Schmidbaur, A. Schier, Chem. Soc. Rev., 2012, 41, 370-412.[4] C. Lavenn, N. Guillou, M. Monge, D. Podbevšek, G. Ledoux, A. Fateeva, A. Demessence, Chem. Commun., 2016, 52, 9063-9066.

SSCI-VIDE+CDFA+ADM:OVE; International audience; Hybrid Au(I) compounds exhibit a large domain of applications such as electronic devices, contrast agents,sensors or photocatalysts. These applications are related to the ability of gold(I) to form aurophilic interactionsimplying self-assembly and luminescence.1 Among them, gold(I) thiolates are an important class of materials due tothe high affinity of gold for sulfur atoms that can generate oligomers or polymers. However due to the fast precipitationand the insolubility of these solids, a little is known about their structure and the origin of the photoluminescence. Wepresent the syntheses and the first structure resolutions, by powder X-Ray diffraction, of series of gold(I)-thiophenolate-based compounds. Depending on the substituent different structures are obtained: lamellar, helicoidalor cyclic (Fig. 1a). The photophysical properties of these hybrid materials are studied in solid-state and coupled withDFT calculations. These analyses show that the charge transfer from Ligand-to-Metal or Metal-to-Ligand and thequantum yield from few percentage to 70%, can be tuned with the electrophilicity of the thiolates.2-3 Among thosecoordination polymers, two exhibit dynamic OFF/ON emission switching, one associated with a thermally inducedsolid-state phase change from amorphous to crystalline2 and the other one from a reversibleesterification/saponification. Finally we synthesized luminescent, crystalline and flexible fibers of [Au(SPh)]n andgenerated by calcination composite materials mixing gold nanoparticles (GNP) and fibers (Fig. 1b and c). This studyshows the great potential of gold thiolates as phosphorescent hybrid materials and as precursors for the formation ofmultifunctional nanocomposites coupling plasmonic and luminescence in electronic devices or photocatalysis.

SSCI-VIDE+CDFA+OVE:ADM; National audience; Les composés hybrides à base d’Au(I) présentent un vaste domaine d'applications, comme dispositifs électroniques, agents de contraste, capteurs, photocatalyseurs ou produits d'intérêt biologique et pharmaceutique. Ces propriétés proviennent en grande partie de la capacité de l'or (I) à former des interactions aurophiques impliquant l'auto-assemblage des structures et de la photo-luminescence.[1] Parmi ces composés hybrides, les thiolates d'or(I), [Au(SR)]n, sont une classe importante de matériaux que l’on trouve soit dans la formation de nanoparticules d’or, soit dans la chimie de coordination. Toutefois la grande affinité de l’or et du soufre implique souvent la formation rapide de produits insolubles. C’est surtout le cas pour les espèces polymériques neutres. Ainsi, le nombre de structures de polymères de coordination [Au(SR)]n reste relativement limité.[2]Notre étude porte sur l’utilisation de la résolution de structure à partir de diagrammes de DRX sur poudre de nouveaux composés bidimentionnels [Au(SPhCO2R)]n (R = H, Me). [3], [4] Selon la structure et la fonctionnalisation du ligand ces composés présentent des propriétés de photoémission différentes. Certains possèdent un rendement quantique d’émission supérieur à 70 % et l’un d’entre eux présente un comportement de thermoluminochromisme dû à l’émission double intrinsèque. Cette propriété rend ce dernier intéressant pour la mesure optique de la température avec une très bonne sensibilité et sur une gamme de température importante.De plus, récemment, nous avons mis à jour une nouvelle voie de synthèse de thiolates d'or(I) cristallins à partir d’une phase isomère amorphe par chauffage à l’état solide [5]. Pour comprendre la transition de phase qui est associée à l’apparition de l’émission, nous allons présenter quelques-unes de nos récentes conclusions émises grâce à l’utilisation de la fonction de distribution de paires (PDF). La PDF se révèle être un outil très puissant pour l’étude de phases amorphes de polymères de coordination.[6]

SSCI-VIDE+CDFA+WSA:OVE:ADM; International audience; Hybrid Au(I) compounds exhibit a large domain of applications such as electronic devices, contrast agents, sensors or photocatalysts. These applications are related to the ability of gold(I) to form aurophilic interactions implying self-assembly and luminescence.[1] Among them, gold(I) thiolates are an important class of materials due to the high affinity of gold for sulfur atoms that can generate oligomers or polymers. Depending on the organic substituent of the thiolate, different structures can be obtained: lamellar, helicoidal (Figure a) or cyclic. Recently, a series of gold(I)-thiophenolate-based coordination polymers have shown a thermally induced phase change in the solid state (Figure b and c). The transition from an amorphous phase to a crystalline one is associated with the modification of the photophysical properties (luminescence) to generate a switch of the emission.[2] These photophysical properties are studied in solid-state (Figure d) and coupled with DFT calculations. Tuning the synthesis of gold(I)-thiophenolate allows the formation of luminescent, crystalline and flexible fibers which can generate a composite material mixing gold nanoparticles and crystalline fibers by calcination. This study shows the great potential of gold thiolates as phosphorescent hybrid materials and as precursors for the formation of multifunctional nanocomposites coupling plasmonic and luminescence in electronic devices or photocatalysis.

SSCI-VIDE+CDFA+ADM; National audience; None

International @ MATERIAUX+ADM; International audience; Polynuclear hybrid Au(I) compounds exhibit a very large domain of applications such as electronic devices, contrast agents, sensors or photocatalysts. All these applications are related to the ability of gold(I) to form aurophilic interactions which give luminescent materials.[1] Among hybrid gold species, gold(I) thiolate compounds are an important class of materials due to the high affinity of gold for sulfur atoms that can generate molecular complexes, extended polymers, stabilized gold nanoparticles or self-assembled monolayers. Thus in nanoscience, gold(I) thiolate polymers are a key step in the Brust-Schiffrin synthesis of functionalized gold nanoparticles.[2] However relatively little is known about the relationship between the structure of the Au(I)-SR intermediate and the formation of the nanoparticles. In addition, the luminescence of gold thiolate nanoclusters, with gold core diameter less than 2 nm, is highly dependent of the structure, the arrangement and the length of Au(I)-thiolate motifs at the surface.[3] So to understand the formation of gold thiolate nanoparticles and clusters and also to explain the luminescence of gold thiolate coordination polymers and clusters, we will present the syntheses and the first structure resolutions, by powder X-Ray diffraction, of series of [Au(I)-SR]n compounds. We will demonstrate that depending on the substituent (R = Ph, PhCOOH, PhNH2) different structures are obtained: lamellar, helicoidal or cyclic. The photophysical properties governed by aurophilic inetractions and Ligand-to-Metal Charge Transfer are studied by room temperature and solid-state emission and lifetime decay experiments, and are explained by DFT calculations. Among those coordination polymers, two exhibit dynamic OFF/ON emission switching, one associated with an irreversible solid-state thermal crystallization and the other one from a reversible esterification. In addition we will show, from those preformed coordination polymers, that exchange reactions of thiol ligands involve dissolution/recrystallization mechanism, pointing out that each thiolate ligand induces its own polymeric structure. REFERENCES[1]Schmidbaur H., Schier A., Chem. Soc. Rev., 41, (2012), 370. [2]Lavenn, C.; Albrieux, F.; Tuel, A.; Demessence, A., J. Colloid Interface Sci., 418, (2014), 234.[3]Luo Z., Yuan X., Yu Y., Zhang Q., Tai Leong D., Yang Lee J., Xie J., J.Amer. Chem. Soc., 134, (2012), 16662. Das A., Li T., Li G., Nobusada K., Zeng C., Rosi N. L., Jin R., Nanoscale, 6, (2014), 6458.

International @ MATERIAUX+CLA:JUC:ADM; International audience; Polynuclear hybrid Au(I) compounds exhibit a very large domain of applications such as electronic devices, contrast agents, sensors or photocatalysts. All these applications are related to the ability of gold(I) to form aurophilic interactions which gives luminescent materials [1]. Among gold species, thiolate gold(I) compounds are an important class of materials due to the high affinity of gold for sulfur that can generate molecular complexes, extended polymers, stabilized gold nanoparticles or SAM. Thus in nanoscience, thiolate gold(I) polymers are a key step in the Brust synthesis of functionalized gold nanoparticles. However relatively little is known about the relationship between the structure of the Au(I)-SR intermediate and the formation of the nanoparticles. Thus the luminescence of thiolate gold nanoclusters, with gold core diameter less than 2 nm, are highly dependent of the structure and the arrangement of Au(I)-thiolate motifs at the surface [2]. So to understand the luminescence and the formation of gold clusters, we will present the synthesis and the first structure resolutions by powder X-Ray diffraction of series of [Au(I)-SR]n coordination polymers. We will demonstrate that depending on the substituent (R = Ph, PhCOOH, PhNH2, PhtBu, naphthalene, C11H23, C2H4Ph…) different structures are obtained (lamellar, helicoidal or cyclic) with luminescent properties governed by Au-Au distances [3]. Reduction of these crystalline coordination polymers to form functionalized gold nanoparticles will also be reported and will contribute to a better control of gold nanoparticles preparation.

The aim of this double-blind, placebo-controlled, randomized, cross-over pilot study was to assess the antiinflammatory properties of cetirizine. A group of 27 patients with a positive patch test to an allergen consecutively received cetirizine 10 mg o.d. or placebo during a 14-day period, respectively. At day 11 of each period, patch testing was performed with the allergen. The image analysis showed a skin reaction significantly reduced under cetirizine (p = 0.03), but the clinical recording and the standardized chromatometry did not show any difference between groups. In the cross-over analysis the results of image analysis were influenced by the period, but this effect disappeared after adjustment of the ambient temperature during the 3 days of the test. These results demonstrate that cetirizine has an impact on the inflammatory process in a clinical model of cell-mediated allergic reaction, although this effect is only detected with a very sensitive technique. They also show that it is useless to stop antihistamines before patch testing, since clinical evaluation of tests is not hampered by a potent antihistamine. Additionally this study suggests that ambient temperature has an influence on the results of tests.

International audience; *