The preparation and characterisation of rhodium(III) and Iridium(III) half sandwich complexes with napthalene-1,8-dithiolate, acenaphthene-5,6-dithiolate and biphenyl-2,2′-dithiolate

The synthesis of rhodium(III) and iridium (III) half sandwich complexes [Cp*M(PEt3) (S-R-S)], M = Rh, Ir; S-R-S = naphthalene-1,8-dithiolate (NaphthS2, a), acenaphthene-5,6-dithiolate (AcenapS2, b) and biphenyl-2,2′-dithiolate (BiphenS2, c) is reported. We also describe the isolation of a new compound acenaphthene-1,8-dithiol. All complexes have been fully characterised using multinuclear NMR spectroscopy and single crystal X-ray diffraction. The ligands naphthalene-1,8-dithiol (H2a), acenaphthene-1,8-dithiol (H2b), 1,1′-biphenyl-2,2′-dithiol (H2c) and benzene-1,2-dithiol (H2d) have also been characterised by single crystal X-ray diffraction.PostprintPeer reviewe

Main group tellurium heterocycles anchored by a P2VN2 scaffold and their sulfur/selenium analogues

The authors are grateful to the EPSRC, the EPSRC National Mass Spectrometry Service Centre (NMSSC) Swansea, the School of Chemistry St. Andrews, EaStCHEM, and NSERC Canada for financial support.A comprehensive investigation of reactions of alkali-metal derivatives of the ditelluro dianion [TePV(NtBu)(μ-NtBu)]22– (L2–, E = Te) with p-block element halides produced a series of novel heterocycles incorporating P2VN2 rings, tellurium, and group 13–16 elements. The dianion engages in Te,Te′-chelation to the metal center in Ph2Ge and R2Sn (R = tBu, nBu, Ph) derivatives; similar behavior was noted for group 14 derivatives of L2– (E = S, Se). In the case of group 13 trihalides MCl3 (M = Ga, In), neutral spirocyclic complexes (L)M[NtBu(Te)PV(μ-NtBu)2PIIIN(H)tBu)] (M = Ga, In) comprised of a Te,Te′-chelated ligand L2– and a N,Te-bonded ligand resulting from loss of Te and monoprotonation were obtained. In reactions with RPCl2 (R = tBu, Ad, iPr2N) a significant difference was observed between Se- and S-containing systems. In the former case, Se,Se′-chelated derivatives were formed in high yields, whereas the N,S-chelated isomers predominated for sulfur. All complexes were characterized by multinuclear (1H, 31P, 77Se, 119Sn, and 125Te) NMR spectroscopy; this technique was especially useful in the analysis of the mixture of (L)(Se) and (L)(SeSe) obtained from the reaction of Se2Cl2 with L2– (E = Te). Single-crystal X-ray structures were obtained for the spirocyclic In complex (9), (L)GePh2 (E = Te, 10), (L)SntBu2 (E = Te, 12a); E = Se, 12aSe, E = S, 12aS) and (L)(μ-SeSe) (E = Te, 16).PostprintPostprintPeer reviewe

Synthesis and structural characterization of Zn2+, Cd2+ and Hg2+ complexes with tripyrrolidinophosphine chalcogenides

Authors are grateful to the Tunisian Ministry of High Education and Scientific Research for support [grant number: LR99ES14] and to the French Service for Cooperation and Cultural Action (SCAC) in Nouakchott, Mauritania for a scholarship to KE.Six new complexes of zinc(II), cadmium(II) and mercury(II) chlorides with tripyrrolidinophosphine chalcogenides of the types [MCl2(Pyrr3PE)2] (M = Zn, E = S (1) or E = Se (2); M = Cd, E = S (3) or E = Se (4)) and [{HgCl(Pyrr3PE)}2(µ-Cl)2] (E = S (5) or Se (6)) have been prepared in yields of 66-92% by reaction of the ligands with metal chloride in ethanol and characterized by 1H and 31P NMR, IR, elemental analysis, conductivity, and single crystal X-ray diffraction analysis. The results show that the complexes are pseudo-tetrahedral containing coordinated chloride ions. Interestingly, the X-ray studies reveal that while the title ligands produce dinuclear complexes with Hg, their Cd and Zn complexes are mononuclear. The tetrahedral bond angles vary from 85.69(5)° to 126.25(4)° in dinuclear complexes 5 and 6 and from 93.51(3)° to 117.38(3)° in mononuclear species 2-4. The E = S bond lengths are in the range 1.999(9)-2.198(2) Å. The coordination properties of the title ligands are discussed and compared to those obtained for their bulkier counterparts.PostprintPeer reviewe

Site-Specific Iron Substitution in STA-28, a Large Pore Aluminophosphate Zeotype Prepared by Using 1, 10-Phenanthrolines as Framework-Bound Templates

An AlPO4 zeotype has been prepared using the aromatic diamine 1, 10-phenanthroline and some of its methylated analogues as templates. In each case the two template N atoms bind to a specific framework Al site to expand its coordination to the unusual octahedral AlO4N2 environment. Furthermore, using this framework-bound template, Fe atoms can be included selectively at this site in the framework by direct synthesis, as confirmed by annular dark field scanning transmission electron microscopy and Rietveld refinement. Calcination removes the organic molecules to give large pore framework solids, with BET surface areas up to 540 m2 g-1 and two perpendicular sets of channels that intersect to give pore space connected by 12-ring openings along all crystallographic directions

The Synthesis of [{n-Bu2Sn(S2N2)}2] and its use in the preparation of Organometallic Iridium Sulfur Nitrogen Complexes

The addition of [n-Bu2SnCl2] to a solution of [S4N3][Cl] in liquid ammonia gave after extraction of the dry reaction mixture the new tin disulfur dinitrido compound [{n-Bu2Sn(S2N2)}(2)] (1). Reaction of [{n-Bu2Sn(S2N2)}(2)] (1) with the pentamethylcyclopentadienyl (Cp*) iridium derivatives [{IrCl(mu-Cl)(eta(5)-C5Me5)}(2)] or [(eta(5)-C5Me5)IrCl2(PPh3)] gave different products, which were dependent on the reactant ratios. A 1:1 reaction between 1 and [{IrCl(mu-Cl)(eta(5)-C5Me5)}(2)] gave only [(eta(5)-C5Me5)Ir(S2N2)] (2) in moderate yield; the same product in higher yield was obtained from a 2:1 reaction between 1 and [(eta(5)-C5Me5)IrCl2(PPh3)]. Reaction of 1 and [(eta(5)-C5Me5)(2)IrCl2(PPh3)] (1:1 molar ratio) in the presence of NH4[PF6] gave the unusual bimetallic species [(eta(5)-C5Me5)IrCl(PPh3)(S2N2)Ir(eta(5)-C5Me5)][PF6] (3). The X-ray crystal structures of 1, 2, and 3 are reported.PostprintPeer reviewe

A Boron, Nitrogen, and Oxygen Doped π-Extended Helical Pure Blue Multiresonant Thermally Activated Delayed Fluorescent Emitter for Organic Light Emitting Diodes That Shows Fast kRISC Without the Use of Heavy Atoms

Narrowband emissive multiresonant thermally activated delayed fluorescence (MR-TADF) emitters are a promising solution to achieve the current industry-targeted color standard, Rec. BT.2020-2, for blue color without using optical filters, aiming for high-efficiency organic light-emitting diodes (OLEDs). However, their long triplet lifetimes, largely affected by their slow reverse intersystem crossing rates, adversely affect device stability. In this study, a helical MR-TADF emitter (f-DOABNA) is designed and synthesized. Owing to its π-delocalized structure, f-DOABNA possesses a small singlet-triplet gap, ΔEST, and displays simultaneously an exceptionally faster reverse intersystem crossing rate constant, kRISC, of up to 2 × 10⁶ s⁻¹ and a very high photoluminescence quantum yield, ΦPL, of over 90% in both solution and doped films. The OLED with f-DOABNA as the emitter achieved a narrow deep-blue emission at 445 nm (full width at half-maximum of 24 nm) associated with Commission Internationale de l'Éclairage (CIE) coordinates of (0.150, 0.041), and showed a high maximum external quantum efficiency, EQEmax, of ≈20%

Synthesis and characterisation of Au(I)-(ITent) complexes

The ERC (Advanced Investigator Award-FUNCAT), the EPSRC and Syngenta are gratefully acknowledged for support of this work. Umicore AG is acknowledged for their generous gift of auric acid. S.P.N. is a Royal Society Wolfson Research Merit Award holder.The synthesis of novel [AuCl(ITent)] and [Au(OH)(ITent)] complexes is reported. They have been fully characterised and their steric parameters were assessed by calculating percent buried volumes and producing steric maps from their crystal structures in the solid state.PostprintPeer reviewe

Hydrofluorination of alkynes catalysed by gold bifluorides

The ERC (Advanced Investigator Award FUNCAT and PoC award GOLDCAT), the EPSRC and Syngenta are gratefully acknowledged for support of this work. Umicore AG is acknowledged for their generous gift of auric acid. S.P.N. is a Royal Society Wolfson Research Merit Award holder.We report the synthesis of nine new N-heterocyclic carbene gold bifluoride complexes starting from the corresponding N-heterocyclic carbene gold hydroxides. A new methodology to access N,N′-bis(2,6-diisopropylphenyl)imidazol-2-ylidene gold(I) fluoride starting from N,N′-bis(2,6-diisopropylphenyl)imidazol-2-ylidene gold(I) hydroxide and readily available potassium bifluoride is also reported. These gold bifluorides were shown to be efficient catalysts in the hydrofluorination of symmetrical and unsymmetrical alkynes, thus affording fluorinated stilbene analogues and fluorovinyl thioethers in good to excellent yields with high stereo- and regioselectivity. The method is exploited further to access a fluorinated combretastatin analogue selectively in two steps starting from commercially available reagents.Publisher PDFPeer reviewe

Synthesis of homoleptic and heteroleptic bis-N-heterocylic carbene group 11 complexes

A straightforward synthetic route has been developed permitting the formation of homoleptic and heteroleptic bis-N-heterocyclic carbene metal complexes. The methodology has proven efficient for all group 11 members. These complexes are easily synthesized using [M(Cl)(NHC)] with different NHC salts in the presence of inexpensive bases such as sodium hydroxide. These systems were fully characterized and displayed high stability even in the presence of light