Triarylborane Functionalized Dicyanovinyl and Acetylacetone Based Molecular Platforms: Building Blocks for Multiple Anion Sensors and Efficient Phosphorescence Emitters The main objective of this thesis is to design a simple strategy for triarylborane based multiple anion sensors and development of triarylborane incorporated phosphorescent metal complexes. The thesis consists of eight chapters and the contents of each chapter are given below. Chapter 1 This chapter gives a general introduction to recent advances relevant to the theme of the thesis. A review of the fundamental characteristics of triarylboranes and their applications in various fields such as chemical sensors and optoelectronics is presented. Advances in boron chemistry in the areas such as anion sensors, solid state emissive and phosphorescence materials are discussed in detail. The scope of the thesis is outlined at the end of the chapter. Chapter 2 The second chapter deals with the general experimental techniques and synthetic procedures followed in this thesis. Chapter 3 This chapter deals with a rational design strategy for differential identification of fluoride and cyanide ions using TAB based sensors. In general, most of the triarylboranes give similar optical responses towards fluoride and cyanide ions as they follow similar sensing mechanism. In order to circumvent this problem, two TAB-DCV conjugates (1 and 2) are designed and synthesised. The DCV unit is highly specific for cyanide ion owing to the presence of electrophilic carbon center. Probes 1 and 2 differ in steric crowding around the boron center. The less crowded boron center in 1 binds with fluoride as well as with cyanide ions giving similar optical response (luminescence is quenched in presence of F¯ and CN¯). In the case of 2, selectivity of boron center towards fluoride is tuned by increasing the steric crowding around the boron unit. The dicyanovinyl unit acts as selective sensing site for cyanide ions. As a result, 2 gives different fluorogenic response towards the anions F¯ and CN¯ which were considered as interfering anions in TAB based sensor chemistry. Thus, a modular design principle is developed for differential identification of fluoride and cyanide ions using TAB. Chapter 4 In this chapter, detailed photophysical studies of TAB-amine-DCV conjugates and colorimetric discrimination of fluoride and cyanide ions are discussed. Presence of amine based donor between the two electron deficient sites enhances the electronic conjugation in 3−5. Since there are two different acceptor sites with a common donor, two distinct charge transfer transition bands are observed in the visible region of electromagnetic spectrum. The absorption and emission spectra of these compounds show pronounced sensitivity to solvent polarity, signifying large excited state dipolmonents. Anion binding studies confirms that these compounds are highly selective towards fluoride and cyanide ions. Fluoride ions selectively interact with boron center and block the corresponding charge transfer transition thereby leading to a distinct colour change which is observable by naked eye. On the other hand, cyanide interacts with boron as well as DCV unit and blocks both the charge transfer transitions which results in disappearance of colour. Hence, compounds 4 and 5 exhibit different colorimetric signals for fluoride and cyanide ions. Since the absorption bands of 3 do not fall in the visible region, it does not show any colorimetric response towards the aforementioned anions. The anion sensing mechanisms are established by 1H, and 19F NMR studies. Chapter 5 This chapter presents a systematic study of the effect of length of π-electronic conjugation on the optical properties and anion sensing abilities of a series of TAB-oligothiophene-DCV conjugates (6−8). Their absorption as well as emission bands undergo redshift upon increasing the number of thiophene units between TAB and DCV units as the π-electronic conjugation in 6−8 is greatly dependent on the number of thiophene units. Their fluorescence emission is highly sensitive to solvent polarity. In the case of 6, the emission band undergoes a redshift with reduced intensity. In the case of 7 the emission band undergoes a redshift but the intensity is not affected by solvent polarity. In the case of 8, the emission band undergoes redshift with enhanced intensity in polar solvents. Interestingly, 7 and 8 show solvent viscosity dependent fluorescence. Structural reorganisation is restricted in viscous medium and results in enhanced emission for 7 and 8. Further, these compounds exhibit selective response towards the fluoride and cyanide ions with different colorimetric responses. Test strips made up of probes 7 and 8 have potential application in identifying fluoride and cyanide ions in aqueous medium. Chapter 6 This chapter describes synthesis and optical characterisation of triarylborane incorporated acetylacetone (acacH) ligands (9, 10) and their borondifluoride complexes (11, 12). AcacH ligands and BF2 complexes show solvent dependent emission phenomena due to the involvement of charge transfer transition. Their optical properties are highly dependent on molecular conformations. Complex with duryl spacer (12) exhibits more red shifted emission in polar solvents due to the enhanced charge transfer transition facilitated by twisted rigid geometry. In presence of fluoride and cyanide ions, the borondifluoride complexes are not stable. The anions concomitantly interact with tricoordinate boron as well as acac-BF2 unit to give rise to complex pattern of photoluminescence spectral changes during the titration experiment. The binding pathway and the possible species involved are established with the help of 1H, 19F and 11B NMR spectral studies in presence of the anions. Complexes 11 and 12 act as selective chemodosimetric sensors for fluoride and cyanide ions. Chapter 7 In this chapter, the synthesis and optical characterisations of triarylborane conjugated cyclometalated platinum complexes are discussed. A series of square planar platinum complexes are synthesised with different cyclometalating ligands. Complexes (13−18) exhibit a range of luminescence from green to red in solution as well as in the solid state. Their emission intensities are highly sensitive towards atmospheric oxygen suggesting that they originate from a triplet excited state. A maximum of 85% quantum yield is observed for complex 15 in solution state while complex 14 showed a maximum of 58% quantum yield in solid state. Complexes with rigid molecular conformation (14, 16 and 18) showed higher luminescence quantum yield than those having phenyl spacer (13, 15 and 17). The sterically encumbered boryl (-BMes2) group significantly reduces π-π stacking between the square planar entities. Thus, complexes 13−18 show bright luminescence in solid state compared to model complexes without boryl group. The effect of Lewis acidic boron center on luminescence behaviour is explored by fluoride binding studies. Chapter 8 This chapter is divided into two parts. Part-I describes the synthesis and optical characterisation of triarylborane conjugated cyclometalated iridium complexes (19−24). They are brightly luminescent in solution state with high sensitivity towards atmospheric oxygen. Complex 20 shows a highest quantum yield of 91%. Interestingly, under ambient atmospheric conditions, they exhibit a rare type of dual emission. Life time data suggest that the lower energy emission band originates from cyclometalated iridium based triplet excited state while higher energy emission band originates from boryl ased singlet excited state. Fluoride binding at the boron site results in luminescence quenching; evidently, tri-coordinate boron has a major contribution to the luminescence features of these iridium complexes. Part-II deals with synthesis of triarylborane conjugated pyrazole ligand (25) and its binuclear iridium complexes (26−28) in which two iridium centers are bridged by hydroxo as well as pyrazolato ligands. These binuclear iridium complexes exhibit higher luminescence quantum yield than TAB-acac-Iridium complexes (mononuclear complexes; part I). Binding of fluoride ions at the boron center has a minor impact on their luminescence nature. High sensitivity of their luminescence towards atmospheric oxygen indicates the involvement of triplet excited state in their emission process.

15N-based nuclear magnetic resonance techniques are considered very powerful to study the molecular properties of platinum-containing anticancer agents, these properties being responsible for the efficacy of the compounds, but also for the understanding of resistance mechanisms and toxicity. Therefore, the first part of the present work aimed to develop a new method for synthesizing 15N-labeled, chiral platinum compounds. A theoretical discussion on the nucleophilic ring-opening of aziridines has also been envisaged, rationalizing an interesting regiochemistry question. Indeed, a surprising inversion of regiochemistry arose during the development of the above-mentioned synthetic pathway, and density functional theory calculation brought a rational framework to the experimental findings.<p><p>Infrared spectroscopy probes the global chemical composition of a sample and has been used to produce a snapshot of cancer cells contents after treatment with platinum coordinates. Indeed, in vitro studies focused here on the use of modern spectroscopic methods to fingerprint the cellular impact of platinum complexes. These drug signatures help to classify and select promising compounds. It makes no doubt that such systemic approaches for compound discovery are helpful technologies. Also, we made the use of the COMPARE algorithm from the NCI, which analyzes similarity between any active compounds previously tested by the NCI large scale in vitro screening program of anticancer agents. <p><p>The last chapter aimed to study the interactions between a series of platinum coordinates and DNA. Binding mode to telomeric-like sequences and binding kinetics to genomic-like sequences were assessed to investigate any differences between the compounds and to gain insight into structure-activity relationships. <p> / Doctorat en Sciences biomédicales et pharmaceutiques / info:eu-repo/semantics/nonPublished

Cette thèse porte sur la synthèse et la caractérisation photophysique d'une série de composés neutres luminescents de platine (II) contenant un ligand tridentate dianionique chromophore N-donneur et un ligand auxiliaire monodentate. Les composés montrent un changement notable des propriétés de photoluminescence selon l'auto-assemblage en raison de la formation d'interactions intermoléculaires non covalentes faibles telles que metal-metal et π-π. Nous avons démontré comment les complexes de Pt (II) peuvent être auto-assemblés d'une manière contrôlée et précise en jouant sur les facteurs cinétiques et thermodynamiques, ainsi que la morphologie des différents ensembles étudiés. Ces approches ont conduit à des matériaux avec des propriétés améliorées et uniques tels que le mécano-chromisme, ainsi que l'absorption et l'émission de la lumière polarisée. Les composés étudiés et leurs assemblages sont utiles non seulement pour le développement de nouveaux matériaux fonctionnels supramoléculaires en équilibre et hors- équilibre, mais aussi pour des applications en bio-imagerie. / This thesis focuses on the synthesis and the photophysical characterization of a series of luminescent neutral Pt(II) compounds containing a tridentate dianionic N-donor chromophoric ligand and a monodentate ancillary moiety. The compounds exhibited notable change of the photoluminescence properties upon self-assembly due to the establishment of weak non-covalent intermolecular interactions – metal-metal and π-π. We demonstrated how Pt(II) complexes can be self-assembled in a controlled and precise manner by playing with kinetic and thermodynamic factors and the morphology of the different assemblies investigated. Such approaches led to materials with enhanced and unique properties such as mechanochromism and polarized light absorption and emission. The investigated compounds and their assemblies were useful for the development of novel functional supramolecular materials in and out of the equilibrium as well as for bioimaging application.

No description available.

This research focused on the development of new metal triimine complexes of Pt(II), Pd(II), and Ni(II) for use in three types of molecular electronic devices: dye sensitized solar cells (DSSCs), organic light-emitting diodes (OLEDs), and organic field effect transistors (OFETs). Inorganic complexes combine many advantages of their chemical and photophysical properties and are processable on inexpensive and large area substrates for various optoelectronic applications. For DSSCs, a series of platinum (II) triimine complexes were synthesized and evaluated as dyes for nanocrystalline oxide semiconductors. Pt (II) forms four coordinate square planar complexes with various co-ligands and counterions and leads to spanning absorption across a wide range in the UV-Vis-NIR regions. When those compounds were applied to the oxide semiconductors, they led to photocurrent generation thus verifying the concept of their utility in solar cells. In the OLEDs project, a novel pyridyl-triazolate Pt(II) complex, Pt(ptp)2 was synthesized and generated breakthrough OLEDs. In the solution state, the electronic absorption and emission of the square planar structure results in metal-to-ligand charge transfer (MLCT) and an aggregation band. Tunable photoluminescence and electroluminescence colors from blue to red wavelengths have been attained upon using Pt(ptp)2 under different experimental conditions and OLED architectures. In taking advantage of these binary characteristics for both monomer and excimer emissions, cool and warm white OLEDs suitable for solid-state lighting have been fabricated. The OFETs project represented an extension of the study of pyridyl-triazolate d8 metal complexes due to their electron-transporting behavior and n-type properties. A prescreening step by using thermogravimetric calorimetry has demonstrated the stability of all three M(ptp)2 and M(ptp)2(py)2 compounds and their amenability to sublimation. Preliminary current-voltage measurements from simple diodes has achieved unidirectional current from a Pt(ptp)2 neat layer and demonstrated its n-type semiconducting behavior.

[Formulae and special characters can only be approximated here. Please see the pdf version of the Abstract for an accurate reproduction.] Several inert platinum complexes were synthesised: [(en)Pt([special character]-dpzm)2Pt(en)]4+, [{Pt(dien)}2[special character]-dpzm]4+, [{Pt(dien)}2[special character]-H2N-(CH2)6-NH2]4+, cis-[(NH3)2Pt([special character]--dpzm)2Pt(NH3)2]4+, trans-[Pt(NH3)2([special character]-dpzm)2]2+. Three active complexes, all with chloro ligands, were also synthesised: trans-[{Pt(NH3)Cl2}2[special character]-dpzm)], trans-[{Pt(NH3)2Cl}2[special character]-dpzm]2+ (di-Pt) and trans-[trans-{Pt(NH3)2Cl}2{trans-[Pt(NH3)2([special character]-dpzm)2]}]4+ (tri-Pt). 1H NMR established that multi-nuclear platinum complexes will preferentially associate in the DNA minor groove with a preference for A/T sequences, and with a binding constant [special character]-105 M-1, regardless of the charge, linking ligand, length or shape. Using [(en)Pt([special character]-dpzm)2Pt(en)]4+ and the oligonucleotide d(GC)5 it was determined that the metal complex binds G/C rich sequences also in the minor groove, but with a much reduced binding constant, 103 M-1. CD studies showed [(en)Pt([special character]-dpzm)2Pt(en)]4+ was able to induce a DNA conformation change from B-type to what appeared to be a partial Z-type. Transcription assays showed that even though the metal complex does not bind DNA covalently, it is still able to inhibit DNA transcription at particular sites. The complexes di-Pt, tri-Pt, [{Pt(dien)}2[special character]-dpzm]4+ and trans-[Pt(NH3)2([special character]-dpzm)2]2+ were tested for anti-cancer activity in the L1210 murine leukaemia cell line, and gave values of 3.8, 2.5, [special character]200 and 64 [special character]M respectively. In the cisplatin resistant line (L1210/DDP), trans-[Pt(NH3)2([special character]-dpzm)2]2+ showed an increase in activity with a drop to 32 [special character]M, while both di-Pt and tri-Pt showed decreases in activity to values of 8.8 and 3.6 [special character]M. In the human ovarian carcinoma 2008 cell line and its cisplatin resistant derivative C13[special character]5, both complexes showed good activity with values of 2.5 and 20.9 [special character]M respectively, but again both showed decreases in activity in the resistant line with values of 17.8 and 37.7 [special character]M respectively. To help explain the difference between activity of these complexes and the complexes BBR3464 and BBR3005, cell uptake and DNA interstrand cross-linking experiments were performed. The cell uptake studies showed that both di-Pt and tri-Pt are taken up by cells at very high levels, when administered at 100 [special character]M, thus indicating that the difference is unlikely to be due to large differences in cell uptake. The DNA interstrand cross-linking studies showed both complexes readily form interstrand adducts (50% interstrand cross-linking at 12 nM and 22 nM respectively, c.f cisplatin 3 [special character]M). These results suggest that the rigid nature of the dpzm linker may be affecting the DNA adducts formed, with more interstrand links being formed than BBR3464. Possibly, it is this that causes the large differences in cytotoxicity. The DNA binding of di-Pt and tri-Pt was examined with the nucleosides adenosine and guanosine and the dinucleotide d(GpG). Both complexes bound at the N7 of guanosine, but 2-fold slower than cisplatin. In addition, di-Pt bound at the N7 and either the N1 or N3 of adenosine, 7-fold slower than guanosine. Di-Pt forms a large variety of cross-links between two d(GpG) molecules, however it could not be established whether the 1,2-intrastrand adduct could be formed. Di-Pt, however, forms a 1,2-GG interstrand adduct with the oligonucleotide d(ATGCAT)2 resulting in a conformation change away from B-type DNA. The sugar pucker of the G3 nucleoside changes from 2[special character]-endo towards 3[special character]-endo, and the position of the nucleotide relative to the sugar changes from anti to syn. The ability of multi-nuclear platinum complexes to form covalent adducts in the DNA minor groove remains unclear. It appears that di-Pt can form up to 33% minor groove adducts with the oligonucleotide d(AT)5, but when added to the oligonucleotide d(GCCAAATTTCCG)2 no definite minor groove adducts are seen and the major adduct appears to be a 1,2-interstrand cross-link between the two A6's or between the G1 and G11. Finally, a study of the encapsulation of platinum complexes within cucurbit[7]uril (Q7) as a means of reducing drug toxicity was made. For complex A and di-Pt, encapsulation of the linker ligand occurred. The effect of Q7 on the rate of hydrolysis of di-Pt was at least a 3-fold reduction as compared to free di-Pt with guanosine. Studies with [{Pt(dien)}2[special character]-dpzm]4+/Q7 and the oligonucleotide d(CGCGAATTCGCG)2 showed that the metal complex could dissociate from the Q7 and associate with the oligonucleotide, where an equilibrium is achieved with 15 % of the metal complex bound to the oligonucleotide and 75 % encapsulated in Q7. Tests in the L1210 and L1210/DDP cancer cell lines showed that di-Pt/Q7 has almost the same activity compared to free di-Pt.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-09-15T12:09:54Z No. of bitstreams: 1 nicollibellottidesouza.pdf: 1508500 bytes, checksum: 7150363e1a046cd4741555cb142f6f21 (MD5) / Approved for entry into archive by Diamantino Mayra (mayra.diamantino@ufjf.edu.br) on 2016-09-26T20:18:43Z (GMT) No. of bitstreams: 1 nicollibellottidesouza.pdf: 1508500 bytes, checksum: 7150363e1a046cd4741555cb142f6f21 (MD5) / Made available in DSpace on 2016-09-26T20:18:43Z (GMT). No. of bitstreams: 1 nicollibellottidesouza.pdf: 1508500 bytes, checksum: 7150363e1a046cd4741555cb142f6f21 (MD5) Previous issue date: 2011-02-22 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A malária é causada por protozoários do gênero Plasmodium e é responsável por 250 milhões de casos e 1 milhão de mortes anualmente. Um dos principais empecilhos para o controle da doença é o desenvolvimento de resistência do parasito aos fármacos comumente usados, o que torna urgente a pesquisa por novos antimaláricos. Nesse contexto, análogos de cloroquina acoplados a 6-mercaptopurina e a alquil aminas e complexos de platina foram avaliados quanto a atividade antimalárica utilizando o teste supressivo descrito por Peters em modelo murino de infecção por Plasmodium berghei NK65. Tais análogos exibiram altos valores de supressão da parasitemia, entre 60% e 94% em comparação com o controle não tradado. Considerando o papel imunossupressor de derivados de purina, o análogo de cloroquina acoplado a 6-mercaptopurina MPQUI foi avaliado quanto a aspectos imunológicos (contagem de leucócitos específicos, dosagem de TNF-α e IL-10), não interferindo na resposta imune tendo como base os parâmetros analisados. Portanto, esses análogos devem ser objetos de futuras pesquisas, podendo fornecer novos antimaláricos, já que apresentaram-se promissores e não influenciaram a resposta imune nos parâmetros analisados. / Malaria is caused by protozoan parasites of the genus Plasmodium and is responsible for 250 million cases and 1 million deaths annually. One of the main obstacles for the disease control is the development of resistance by the parasite to the commonly used antimalarials, what makes the research for new ones urgent. In this context, chloroquine analogs attached to 6-mercaptopurine and to alkyl-amines and platinum complexes were evaluated for their antimalarial activity using the 4-day suppressive test described by Peters which was carried out in mice infected with Plasmodium berghei NK65. These analogs exhibited high values of parasitemia suppression, which ranged from 60% to 94% in comparison to untreated control. Considering the immune suppressor role of purine derivates, the chloroquine analog attached to 6-mercaptopurine MPQUI was evaluated for immunological aspects (specific leukocytes count, TNF-α and IL-10 measurements in sera of mice), revealing no interference in the immune response considering these parameters. Therefore, these analogs may be objects of further research, aiming at new antimalarials, since they were shown to be promising and did not influence the immune response in the parameters analyzed.

Les complexes métalliques des carbènes N-hétérocycliques (NHC) présentent un grand potentiel comme anticancéreux. En particulier, des études in vitro ont confirmés une cytotoxicité supérieure au cisplatine. Dans ce travail, nous avons introduit de la diversité moléculaire à de nouveaux complexes NHC-Pt par coordination de différents ligands NHC. Une deuxième stratégie, la post-fonctionnalisation de complexes de Pt a été étudié par : a) formation d’oxime, notamment avec une urée ciblant le PSMA, b) échange de ligand avec des polyamines hydrosolubles (PEI) ou des pnictogènes (phosphines, arsines, stibines), c) échange d’halogène avec des isotopes de l’iode. Les propriétés cytotoxiques de ces composés ont été évaluées in vitro. In vivo (souris), un complexe PEI-Pt montre une inhibition tumorale similaire à l’oxaliplatine. Néanmoins, aucun effet secondaire n’a été détecté contrairement à l’oxaliplatine (hématomes). Ces résultats ouvrent de nouvelles perspectives dans le domaine des anticancéreux sur la base de platine. / Metal N-Heterocyclic Carbene (NHC) complexes are of great potential for cancer therapy. In particular, in vitro studies confirmed their significantly higher cytotoxicity than cisplatin. In this work, we introduced molecular diversity on new NHC-Pt complexes by coordination of various NHC precursors to platinum. As a second strategy, post-synthetic functionalization of Pt complexes has been fully investigated by: a) oxime formation, e.g. with a PSMA targeting urea derivative, b) ligand exchange reaction with hydrosoluble polyamines (PEI) and pnictogen-based ligands (phosphines, arsines, stibines), c) halogen exchange with iodide isotopesCytotoxic properties of these new compounds were evaluated in vitro. Best candidate was selected for in vivo evaluation on mice model showing for PEI-Pt similar tumour inhibition as oxaliplatin. Besides, no “visual” side effects were detected in contrast to oxaliplatin (hematomas). These outstanding results opened up new perspectives in the field of platinum-based drugs.

Die vorliegende Arbeit beschäftigt sich mit der Stabilisierung von SFx- (x = 2-3) und SOyFz-Liganden (y, z = 1-2) in der Koordinationssphäre von Platinkomplexen, die den N-heterozyklischen Carben- (NHC)-Liganden 1,3-Bis(2,4,6-trimethylphenyl)-2-imidazolinyliden (IMes) besitzen. Die Synthese des SF3-Komplexes trans-[Pt(F)(SF3)(IMes)2] gelang durch Umsetzung von [Pt(IMes)2] mit SF4 oder SF6. Bei der SF6-Aktivierungsreaktion kam es zur Bildung von zusätzlichen fluorierten Nebenprodukten, welche durch den Vergleich mit den jeweiligen unabhängig synthetisierten Verbindungen charakterisiert wurden. Die starke Neigung zur Hydrolyse der SF3-Einheit bei Kontakt mit H2O führte zur Bildung von trans-[Pt(F)(SOF)(IMes)2]. Eine alternative Darstellung des S(=O)F-Komplexes konnte durch Umsatz von [Pt(IMes)2] mit SOF2 erreicht werden. Die S(=O)2F-Komplexe trans-[Pt(X)(SO2F)(IMes)2] (X = F, Cl) mit dem Schwefel in der formalen Oxidationsstufe IV wurden durch die Behandlung von [Pt(IMes)2] mit SO2F2 oder SO2ClF erhalten. Die Oxidation des S(=O)F- zum S(=O)2F-Liganden konnte durch Behandlung mit dem Oxygenierungsreagenz 3-Phenyl-2-(phenylsulfonyl)-oxaziridin (Oxaz) bewerkstelligt werden. Eine Oxidation und zugleich Fluorierung der S(=O)F-Einheit in trans-[Pt(F)(SOF)(IMes)2] wurde durch Behandlung mit XeF2 durchgeführt, wobei ein S(=O)F2-Ligand in trans-[Pt(F)(SOF2)(IMes)2]F(HF)n erhalten wurde. Reaktionen von trans-[Pt(F)(SF3)(IMes)2] mit der Lewis-Säure AsF5 oder einer HF-Quelle lässt die Generierung des SF2-Liganden als Teil der kationischen Komplexe trans-[Pt(F)(SF2)(IMes)2]X (X = F(HF)n-, As2F11-) zu. Eine vergleichbare Reaktivität wurde für trans-[Pt(F)(SO2F)(IMes)2] gefunden, wenn NaBArF4 (BArF4- = Tetrakis-[(3,5-trifluoromethyl)phenyl]borat) oder eine HF-Quelle eingesetzt wurden und infolge einer Fluoridabstraktion die Bildung eines SO2-Liganden in trans-[Pt(F)(SO2)(IMes)2]X (X = F(HF)n-, BArF4-) beobachtet wurde. / This work deals with the stabilisation of SFx- (x = 2-3) and SOyFz entities (y, z = 1-2) in the coordination sphere of platinum complexes bearing the N-heterocyclic carbene (NHC) ligand 1,3-bis(2,4,6-trimethylphenyl) 2-imidazolinylidine (IMes). The synthesis of the SF3 complex trans-[Pt(F)(SF3)(IMes)2] was achieved by converting [Pt(IMes)2] with SF4 or SF6. During the SF6 activation additional fluorinated by-products were formed that were characterised by the comparison with independently synthesised compounds. The strong tendency of the SF3 entity to hydrolyse in contact with H2O led to the formation of trans-[Pt(F)(SOF)(IMes)2]. An alternative synthesis of the S(=O)F complex was done by reaction of [Pt(IMes)2] with SOF2. The S(=O)2F complexes trans-[Pt(X)(SO2F)(IMes)2] (X = F, Cl) bearing sulfur ligands in the formal oxidation state IV were accessed by treatment of [Pt(IMes)2] with SO2F2 or SO2ClF. The oxidation of the S(=O)F to the S(=O)2F ligand was achieved by treatment with the oxygenating reagent 3-phenyl 2-(phenylsulfonyl) oxaziridine (Oxaz). An oxidation and fluorination of the S(=O)F group at the same time was done by treatment of trans-[Pt(F)(SOF)(IMes)2] with XeF2 to yield a S(=O)F2 ligand in trans-[Pt(F)(SOF2)(IMes)2]F(HF)n. Reactions of trans-[Pt(F)(SF3)(IMes)2] with the Lewis acid AsF5 or an HF source led to the generation of a SF2 ligand in trans-[Pt(F)(SF2)(IMes)2]X (X = F(HF)n-, As2F11-). A comparable reactivity was found for trans-[Pt(F)(SO2F)(IMes)2], when treated with NaBArF4 (BArF4- = tetrakis-[(3,5-trifluoromethyl)phenyl]borat) or an HF source to yield a SO2 ligand in trans-[Pt(F)(SO2)(IMes)2]X (X = F(HF)n-, BArF4-) by fluoride abstraction.