Search

Methane (CH4) can be captured in silico with a light atom molecule containing only C, H, Si, O, and B atoms, respectively. A tripodal peri-substituted ligand system was employed, namely, [(5-Ph2B-xan-4-)3Si]H (1, xan = xanthene), which after hydride abstraction (1+) carries four Lewis acidic sites within the cationic cage structure. In a previous study, this system was shown to be able to capture noble gas atoms He–Kr (Mebs & Beckmann 2022). In the corresponding methane complex, 1+CH4, a polarized Si+⋯CH4 contact of 2.289 Å as well as series of (H3)CH⋯O/CPh hydrogen bonds enforce spatial CH4 fixation (the molecule obeys C3-symmetry) and slight activation. A trigonal-pyramidal Si–CHeq3–Hax local geometry is thereby approached with Hax–C–Heq angles decreased to 103.7°. All attempts to replace the Lews acidic –BPh2 fragments in 1 with basic –PR2 (R = Ph, tBu) fragments indeed increased intra-molecular hydrogen bonding between host molecule and CH4, and thus caused stronger activation of the latter, however ultimately resulted in the formation of energetically favorable quenched structures with short P–Si contacts, making CH4 binding hard to achieve. The electronic situation of two hypothetic methane complexes, 1+CH4 and [(5-tBu2P-xan-4-)3SiCH4]+ (2+CH4), was determined by a set of calculated real-space bonding indicators (RSBIs) including the Atoms-In-Molecules (AIM), non-covalent interactions index (NCI), and electron localizability indicator (ELI-D) methods, highlighting crucial differences in the level of activation. The proposed ligand systems serve as blueprints for a more general structural design with adjustable trigonal ligand systems in which central atom, spacer fragment, and functional peri-partner can be varied to facilitate different chemical tasks.

Intermolecular interactions of the new drug candidate sila-ibuprofen are investigated in the crystal and in the enzyme cyclooxygenase-II., Sila-ibuprofen is a new potential nonsteroidal anti-inflammatory drug which deviates from its parent ibuprofen in terms of the electrostatic potential around the carbon/silicon-switched C/Si—H group. Therefore, sila-ibuprofen is more water soluble and has a lower melting enthalpy. However, its binding and inhibition properties of cyclooxygenases appear to be very similar to regular ibuprofen. Therefore, in this study, intermolecular interactions and interaction densities of both ibuprofen and sila-ibuprofen in their biologically active forms, i.e. deprotonated and as the pure S-enantiomers are investigated. Quantum-crystallographically refined salts with argininium and 1-phenyl­ethan-1-amoninium (PEA) counter-cations as crystalline models of the interactions with the guanidine functional group of arginine inside cyclooxygenases are presented. The similarities and differences between the polarization of ibuprofen and sila-ibuprofen in the crystal, enzyme, solvent and isolated environments are discussed based on quantum-chemical calculations. For the explicit crystal and enzyme environments, specifically, molecular dynamics simulations starting from the crystal models were combined with QM/MM calculations.

Sterically encumbered bis(m-terphenyl)chalcogenides, (2,6-Mes2C6H3)E (E = S, Se, Te) were obtained by the reaction of the chalcogen tetrafluorides, EF4, with three equivalents of m-terphenyl lithium, 2,6-Mes2C6H3Li. The single electron oxidation of (2,6-Mes2C6H3)2Te using XeF2 / K[B(C6F5)4] afforded the radical cation [(2,6-Mes2C6H3)2Te][B(C6F5)4] that was isolated and fully characterized. The electrochemical oxidation of the lighter homologs (2,6-Mes2C6H3)2E (E = S, Se) was irreversible and impaired by rapid decomposition.

Protocols for the synthesis of the bulky polyfluorinated triarylboranes 2,6‐(C6F5)2C6F3B(C6F5)2 (1), 2,6‐(C6F5)2C6F3B[3,5‐(CF3)2C6H3] (2), 2,4,6‐(C6F5)3C6H2B(C6F5)2 (3), 2,4,6‐(C6F5)3C6H2B[3,5‐(CF3)2C6H3] (4) were developed. All boranes are water tolerant and according to the Gutmann‐Beckett method, 1–3 display Lewis acidities larger than that of the prominent B(C6F5)3., Water tolerant boranes: The synthesis and characterization of bulky polyfluorinated triarylboranes 2,6‐(C6F5)2C6F3B(C6F5)2 (1), 2,6‐(C6F5)2C6F3B[3,5‐(CF3)2C6H3] (2), 2,4,6‐(C6F5)3C6H2B(C6F5)2 (3), 2,4,6‐(C6F5)3C6H2B[3,5‐(CF3)2C6H3] (4) is presented. Unlike the prominent B(C6F5) („BCF“), 1–4 are water tolerant and 1–3 even show larger Lewis acidities, as determined by the Gutmann‐Beckett method.

Transiente, aus Bis(m-terphenyl)fluorpniktogenendurch Fluorid-Abstraktion gebildete Phosphenium- und Ar-senium-Ionen vollzogen einen intramolekularen elektrophilenAngriff, gefolgt von einer Methylgruppenwanderung und bil-deten isolierbare 9-Phospha- und 9-Arsena-Fluorenium-Ionen.

Herein, we report a semiconductive, proton-conductive, microporous hydrogen-bonded organic framework (HOF) derived from phenylphosphonic acid and 5,10,15,20‐tetrakis[p‐phenylphosphonic acid] porphyrin (GTUB5). The structure of GTUB5 was characterized using single crystal X-ray diffraction. A narrow band gap of 1.56 eV was extracted from a UV-Vis spectrum of pure GTUB5 crystals, in excellent agreement with the 1.65 eV band gap obtained from DFT calculations. The same band gap was also measured for GTUB5 in DMSO. The proton conductivity of GTUB5 was measured to be 3.00 × 10−6 S cm−1 at 75 °C and 75% relative humidity. The surface area was estimated to be 422 m2 g−1 from grand canonical Monte Carlo simulations. XRD showed that GTUB5 is thermally stable under relative humidities of up to 90% at 90 °C. These findings pave the way for a new family of organic, microporous, and semiconducting materials with high surface areas and high thermal stabilities., Research in hydrogen-bonded organic frameworks (HOFs) has gained interest in recent years due to their facile design and synthesis but no semiconducting HOF has been reported to date. Here the authors report a thermally stable and proton-conductive organic semiconductor based on a porphyrin HOF.

This review is divided into three different parts. In the introduction, the current applications of metal‐organic frameworks (MOFs) are shown. Furthermore, the overall stability, a comparison of phosphonate MOFs with carboxylate MOFs, the structural richness of phosphonate MOFs with the challenge in synthesis and different linker geometries is discussed. In the second part, several phosphonate MOFs with Y‐shaped planar, X‐shaped planar, and X‐shaped tetrahedral linker systems are described. The final part discusses different structures of inorganic building units (IBUs) with different metal atoms and a comparison of the formed MOF structures.

Herein, we report on the synthesis of a microporous, three-dimensional phosphonate metal-organic framework (MOF) with the composition Cu 3 (H 5 -MTPPA) 2 ·2 NMP (H 8 -MTPPA = methane tetra- p -phenylphosphonic acid and NMP = N-methyl-2-pyrrolidone). This MOF, termed TUB1, has a unique one-dimensional inorganic building unit composed of square planar and distorted trigonal bipyramidal copper atoms. It possesses a (calculated) BET surface area of 766.2 m 2 /g after removal of the solvents from the voids. The Tauc plot for TUB1 yields indirect and direct band gaps of 2.4 eV and 2.7 eV, respectively. DFT calculations reveal the existence of two spin-dependent gaps of 2.60 eV and 0.48 eV for the alpha and beta spins, respectively, with the lowest unoccupied crystal orbital for both gaps predominantly residing on the square planar copper atoms. The projected density of states suggests that the presence of the square planar copper atoms reduces the overall band gap of TUB1, as the beta-gap for the trigonal bipyramidal copper atoms is 3.72 eV.

Kinetic stabilization using bulky m-terphenyl substituents is the key to the isolation of the diarylantimony and diarylbismuth phosphaethynolates (2,6-Mes2C6H3)2EPCO and the related N-heterocyclic carbene complexes (2,6-Mes2C6H3)2EP(O)C(IMe4) (E=Sb, Bi; IMe4=1,3,4,5-tetramethylimidazol-2-ylidene), which have been fully characterized crystallographically and spectroscopically. The experimental characterization was augmented by a DFT based real space bond indicator analysis of the electron density, including AIM, NCI, and ELI-D methods., Zeitschrift für anorganische und allgemeine Chemie, 648 (19), ISSN:1521-3749, ISSN:0044-2313

The N[triple bond, length as m-dash]N triple bond can be cleaved in silico with a light atom molecule containing only the earth abundant elements C, H, Si, and P. Extensive density functional theory (DFT) computations on various classes of peri-substituted scaffolds containing Lewis acidic and basic sites in the framework of frustrated Lewis pairs (FLP) indicate that the presence of two silyl cations and two P atoms in a flexible but not too flexible arrangement is essential for energy efficient N2-activation. The non-bonding lone-pair electrons of the P atoms thereby serve as donors towards N2, whereas the lone-pairs of N2 donate into the silyl cations. Newly formed lone-pair basins in the N2-adducts balance surplus charge. Thereby, the N–N bond distance is increased by astonishing 0.3 Å, from 1.1 Å in N2 gas to 1.4 Å in the adduct, which makes this bond prone to subsequent addition of hydride ions and protonation, forming two secondary amine sites in the process and eventually breaking the N[triple bond, length as m-dash]N triple bond. Potential formation of dead-end states, in which the dications (“active states”) aversively form a Lewis acid (LA)–Lewis base (LB) bond, or in which the LA and LB sites are too far away from each other to be able to capture N2, are problematic but might be circumvented by proper choice of spacer molecules, such as acenaphthalene or biphenylene, and the ligands attached to the LA and LB atoms, such as phenyl or mesityl, and by purging the reaction solutions with gaseous N2 in the initial reaction steps. Charge redistributions via N2-activation and splitting were monitored by a variety of real-space bonding indicators (RSBIs) derived from the calculated electron and electron pair densities, which provided valuable insight into the bonding situation within the different reaction steps.

Noble gas atoms (Ng = He, Ne, Ar, and Kr) can be captured in silico with a light atom molecule containing only C, H, Si, O, and B atoms. Extensive density functional theory (DFT) calculations on series of peri-substituted scaffolds indicate that confined spaces (voids) capable to energy efficiently encapsulate and bind Ng atoms are accessible by design of a tripodal peri-substituted ligand, namely, [(5-Ph2B-xan-4-)3Si]H (xan = xanthene) comprising (after hydride abstraction) four Lewis acidic sites within the cationic structure [(5-Ph2B-xan-4-)3Si]+. The host (ligand system) thereby provides an adoptive environment for the guest (Ng atom) to accommodate for its particular size. Whereas considerable chemical interactions are detectable between the ligand system and the heavier Ng atoms Kr and Ar in the host guest complex [(5-Ph2B-xan-4-)3Si·Ng]+, the lighter Ng atoms Ne and He are rather tolerated by the ligand system instead of being chemically bound to it, nicely highlighting the gradual onset of (weak) chemical bonding along the series He to Kr. A variety of real-space bonding indicators (RSBIs) derived from the calculated electron and pair densities provides valuable insight to the situation of an “isolated atom in a molecule” in case of He, uncovering its size and shape, whereas minute charge rearrangements caused by polarization of the outer electron shell of the larger Ng atoms results in formation of polarized interactions for Ar and Kr with non-negligible covalent bond contributions for Kr. The present study shows that noble gas atoms can be trapped by small light-atom molecules without the forceful conditions necessary using cage structures such as fullerenes, boranes and related compounds or by using super-electrophilic sites like [B12(CN)11]− if the chelating effect of several Lewis acidic sites within one molecule is employed.

The bis(ferrocenyl)phosphenium ion, [Fc2P]+, reported by Cowley et al. (J. Am. Chem. Soc. 1981, 103, 714–715), was the only claimed donor‐free divalent phosphenium ion. Our examination of the molecular and electronic structure reveals that [Fc2P]+ possesses significant intramolecular Fe⋅⋅⋅P contacts, which are predominantly electrostatic and moderate the Lewis acidity. Nonetheless, [Fc2P]+ undergoes complex formation with the Lewis bases PPh3 and IPr to give the donor–acceptor complexes [Fc2P(PPh3)]+ and [Fc2P(IPr)]+ (IPr=1,3‐bis(2,6‐diisopropylphenyl)imidazole‐2‐ylidene)., Lineup of suspects: Interest in kinetically stabilized pnictogenium ions prompted the re‐investigation of the bis(ferrocenyl)phosphenium ion, the only claimed donor‐free divalent phosphenium ion. Iron was found guilty of charge compensation.

Organic light-emitting diodes (OLEDs) are revolutionizing display applications. In this aspect, luminescent complexes of precious metals such as iridium, platinum, or ruthenium still playing a significant role. Emissive compounds of earth-abundant copper with equivalent performance are desired for practical, large-scale applications such as solid-state lighting and displays. Copper(I)-based emitters are well-known to suffer from weak spin-orbit coupling and a high reorganization energy upon photoexcitation. Here we report a cationic organo-copper cluster [Cu4(PCP)3]+ (PCP = 2,6-(PPh2)2C6H3) that features suppressed nonradiative decays, giving rise to a robust narrow-band green luminophore with a photoluminescent (PL) efficiency up to 93%. PL decay kinetics corroborated by DFT calculations reveal a complex emission mechanism involving contributions of both thermally activated delayed fluorescence and phosphorescence. This robust compound was solution-processed into a thin film in prototype OLEDs with external quantum efficiency up to 11% and a narrow emission bandwidth (65 nm fwhm).

A stable ionic κ2Sn,P-coordinated Ru complex shows excellent catalytic activity in aerobic oxidations of benzylamine and benzyl alcohol. This complex is stabilized by a stannylene-phosphine peri-substituted naphthalene ligand, which can act as either a reducing agent for a Ru(III) complex or as a κ2Sn,P-chelating ligand for Ru(II) compounds.

Herein, we report on the synthesis of a microporous, three-dimensional phosphonate metal-organic framework (MOF) of the composition Cu3(H5-MTPPA)2·2 NMP (H8-MTPPA = methane tetra-p-phenylphosphonic acid and NMP = N-methyl-2-pyrrolidone). This MOF, termed TUB1, has a unique one-dimensional inorganic building unit composed of square planar and distorted trigonal bipyramidal copper atoms. It possesses a (calculated) BET surface area of 766.2 m2/g after removal of the solvents from the voids. The Tauc plot for TUB1 yields indirect and direct band gaps of 2.4 eV and 2.7 eV, respectively. DFT calculations reveal the existence of two spin-dependent gaps of 2.60 eV and 0.48 eV for the alpha and beta spins, respectively, with the lowest unoccupied crystal orbital for both gaps predominantly residing on the square planar copper atoms. The projected density of states suggests that the presence of the square planar copper atoms reduces the overall band gap of TUB1, as the beta-gap for the trigonal bipyramidal copper atoms is 3.72 eV.

The condensation of 4,4’-dimethyldiphenylether with tellurium tetrachloride yielded 2,8-dimethyl-10,10-dichlorophenoxatellurine (3), which was characterized by X-ray diffraction. Unlike the parent phenoxatellurine (1) and the 10,10,-dichlorophenoxatellurine (2) showing butterfly conformations, 3 reveals a planar ring structure.

The reaction of (CO)5MnBr with phenoxatellurine (PT) provided the octahedral complex fac-(CO)3(PT)2MnBr in which the two PT ligands are situated in cis-position.

The crystal structures of the salts [Li(1,2-F2C6H4)] [B(C6F5)4] (1) and Cs[B(C6F5)4] (2) comprise six Li···F contacts (1.965(3) − 2.312(3) Å) and twelve Cs···F contacts (3.0312(1) − 3.7397(2) Å), respectively, which are significantly shorter than the sum of van der Waals radii (3.29 and 4.90 Å).

The reaction of 2,6-F2 C6 H3 SiMe3 with Ph2 PLi provided 2,6-(Ph2 P)2 C6 H3 SiMe3 (1), which can be regarded as precursor for the novel anionic tridentate ligand [2,6-(Ph2 P)2 C6 H3 ]- (PCP)- . The reaction of 1 with [AuCl(tht)] (tht=tetrahydrothiophene) afforded 2,6-(Ph2 PAuCl)2 C6 H3 SiMe3 (2). The subsequent reaction of 2 with CsF proceeded with elimination of Me3 SiF and yielded the neutral tetranuclear complex linear-[Au4 Cl2 (PCP)2 ] (3) comprising a string-like arrangement of four Au atoms. Upon chloride abstraction from 3 with NaBArF4 (ArF =3,5-(CF3 )2 C6 H3 ) in the presence of tht, the formation of the dicationic tetranuclear complex linear-[Au4 (PCP)2 (tht)2 ](BArF4 )2 (4) was observed, in which the string-like structural motif is retained. Irradiation of 4 with UV light triggered a facile rearrangement in solution giving rise to the dicationic tetranuclear complex cyclo-[Au4 (PCP)2 (tht)2 ](BArF4 ) (5), which comprises a rhomboidal motif of four Au atoms. In 3-5, the Au atoms are associated by a number of significant aurophilic interactions. The atom-economic and selective reaction of 3 with HgCl2 yielded the neutral trinuclear bimetallic complex [HgAu2 Cl3 (PCP)] (6) comprising significant metallophilic interactions between the Au and Hg atoms. Therefore, 6 may be also regarded as a metallopincer complex [ClHg(AuCAu)] between HgII and the anionic tridentate ligand [2,6-(Ph2 PAuCl)2 C6 H3 ]- (AuCAu)- containing a central carbanionic binding site and two "gold-arms" contributing pincer-type chelation trough metallophilic interactions. Compounds 1-6 were characterized experimentally by multinuclear NMR spectroscopy and X-ray crystallography and computationally using a set of real-space bond indicators (RSBIs) derived from electron density (ED) methods including Atoms In Molecules (AIM), the Electron Localizability Indicator (ELI-D) as well as the Non-Covalent Interaction (NCI) Index.

Fluoride abstraction from bis‐m‐terphenylelement fluorides (2,6‐Mes2C6H3)2EF (E=P, As) generated the highly reactive phosphenium ion [(2,6‐Mes2C6H3)2P]+ and the arsenium ion [(2,6‐Mes2C6H3)2As]+, which immediately underwent intramolecular electrophilic substitution and formation of an 1,2,4‐trimethyl‐6‐mesityl‐5‐m‐terphenyl‐benzo[b]phospholium ion and an 1,2,4‐trimethyl‐6‐mesityl‐5‐m‐terphenyl‐benzo[b]arsolium ion, respectively. The formation of the latter involved a methyl group migration from the ortho‐position of a flanking mesityl group to the meta‐position. This reactivity of [(2,6‐Mes2C6H3)2E]+ (E=P, As) is in sharp contrast to the related stibenium ion [(2,6‐Mes2C6H3)2Sb]+ and bismuthenium ion [(2,6‐Mes2C6H3)2Bi]+, which have been recently isolated and fully characterized (Angew. Chem. Int. Ed. 2018, 57, 10080–10084). On the basis of DFT calculations, a mechanism for the rearrangement of the phosphenium and arsenium ions into the phospholium and arsolium ions is proposed, which is not feasible for the stibenium and bismuthenium ions., The fluoride abstraction from the bis(m‐terphenyl)element fluorides (P, As) using the Lewis acids EtAlCl2 and [Et3Si(toluene)]+, respectively, provided the transient phosphenium and arsenium ion [(2,6‐Mes2C6H3)2As]+ which rearrange readily into the protonated 9‐phospha‐ and 9‐arsena‐fluorenes.

Herein, we report on the synthesis and electronic properties of the phosphonate metal-organic framework (MOF) Cu3(H5-MTPPA)2 (H8-MTPPA = methane tetra-p-phenylphosphonic acid). This MOF, termed TUB1, has a unique one-dimensional inorganic building unit composed of square planar and distorted trigonal bipyramidal copper atoms, and a calculated BET surface area of 766.2 m2/g. The formation of TUB1 reduces the band gap of the linker from 4.2 eV to 2.4 eV. DFT calculations reveal two spin-dependent gaps of 2.60 eV and 0.48 eV for the alpha and beta spins, respectively, and that the lowest unoccupied crystal orbital for both gaps predominantly resides on the square planar copper atoms. Single-crystal conductivity measurements on TUB1 crystals yield an average electrical conductance of 53.2 ± 29.5 S/m. Although the H8-MTPPA linker blocks the extended conjugation in TUB1, we show that the presence of the square planar copper atoms in the inorganic building unit promotes the electrical conductivity.

The aryltellurenyl cation [2‐(tBuNCH)C6H4Te]+, a Lewis super acid, and the weakly coordinating carborane anion [CB11H12]−, an extremely weak Brønsted acid (pK a=131.0 in MeCN), form an isolable ion pair complex [2‐(tBuNCH)C6H4Te][CB11H12], in which the Brønsted acidity (pK a 7.4 in MeCN) of the formally hydridic B−H bonds is dramatically increased by more than 120 orders of magnitude. The electrophilic activation of B−H bonds in the carborane moiety gives rise to a proton transfer from boron to nitrogen at slightly elevated temperatures, as rationalized by the isolation of a mixture of the zwitterionic isomers 12‐ and 7‐[2‐(tBuN{H}CH)C6H4Te(CB11H11)] in ratios ranging from 62 : 38 to 80 : 20., B−H bond activation: The Lewis superacidic aryltellurenyl cation [2‐(tBuNCH)C6H4Te]+ increases the Brønsted acidity of the weakly coordinating carborane anion (CB11H12)− by more than 120 orders of magnitude. Upon heating, the formal B−H bond is converted into an acidic N−H bond, while a Te−B bond is formed. A mechanism for the electrophilic substitution is proposed.

Fluorenyl cations are textbook examples of 4π electron antiaromatic five‐membered ring systems. So far, they were reported only as short‐lived intermediates generated under superacidic conditions or by flash photolysis. Attempts to prepare a m‐terphenyl acylium cation by fluoride abstraction from a benzoyl fluoride gave rise to an isolable 9‐hydroxy fluorenyl cation that formed by an intramolecular electrophilic attack at a flanking mesityl group prior to a 1,2‐methyl shift and proton transfer to oxygen., Surprisingly stable after all: Attempts to prepare a m‐terphenylacylium ion by fluoride abstraction from a benzoyl fluoride, gave rise to a 4π‐electron antiaromatic 9‐hydroxy fluorenyl cation that formed via an intramolecular electrophilic attack at a flanking mesityl group prior to a 1,2‐methyl shift and proton transfer to oxygen.

The synthesis of the new ligand bis(6-diphenylphosphinoacenaphth-5-yl)sulfoxide, [6-(Ph2P)-5-Ace-6](2)-SO (1), is presented along with six transition metal complexes thereof, namely,1 center dot MCl (M = Rh, Cu, Ag, Au) and1 center dot MCl2(M = Ni, Pd). Within these novel complexes, close metal-sulfur distances are observed and the nature of the M-S coordination, as well as the response of the(+)S-O(-)bond, are investigated in detail with a set of spectroscopic, crystallographic and real-space bonding indicators.

The reaction of (6-Ph2P-Ace-5-)2P(O)H with (tht)AuCl3 proceeds via elimination of tetrahydrothiophene (tht) and HCl, providing the zwitterionic PPP-pincer complex (6-Ph2P-Ace-5-)2P(O)AuCl2 (1) as yellow crystals. The molecular structure of 1 was established and studied by X-ray crystallography. The electronic structure was computationally analyzed using a comprehensive set of real-space bonding indicators derived from electron and electron-pair densities, providing insight into the relative contributions of covalent and non-covalent forces to the polar-covalent Au&ndash, Cl, Au&ndash, P, and P&ndash, O&minus, bonds, the latter being one of the textbook cases for strongly polarized covalent interactions. Partial spatial complementarity between both bonding aspects is suggested by the electronic properties of the distinctively different Au&ndash, Cl bonds.

Transient phosphenium and arsenium ions, generated by fluoride abstraction from bis(m‐terphenyl)fluoropnictogens, underwent intramolecular electrophilic attack prior to methyl group migration and gave rise to isolable 9‐phospha‐ and 9‐arsena‐fluorenium ions., Chemical rollercoaster ride: Attempts to prepare phosphenium and arsenium ions of the type [(2,6‐{Me5C6}2C6H3)2E]+ (E=P; E=As) lead to the isolation of two‐isomer mixtures of phospha‐ and arsena‐fluorenium ions. These arenium ions were isolated and structurally characterized. They are high‐energy species that undergo subsequent, solvent‐dependent reactions leading to thermodynamically favored products.

Novel E,C,E'-pincer supported silyl cations (E, E' = O, S, Se, Au) were prepared in three steps starting from 2,6-F2C6H3SiMe2H (1a) and 2,6-Br2C6H3SiMe2H (1b), which were first converted in two complementary ways into 2,6-(Ph2P)(2)C6H3SiMe2H (2). The oxidation of 2 with H2O2 center dot urea, S-8, and Se-8 afforded 2,6-(Ph2PE)(2)C6H3SiMe2H (3a, E = O; 3b, E = S; 3c, E = Se) and 2-(Ph2PE)-6-(Ph2P)-C6H3SiMe2H (4b, E = S; 4c, E = Se), which were reacted to the E,C,E-supported silyl cations [2,6-(Ph2PE)(2)C6H3SiMe2](+) (5a, E = O, counterion Br-3(-); 5b, E = S, counterion B(C6F5)(4)(-); 5c, E = Se, counterion B(C6F5)(4)(-)), the E,C-supported silyl cations [2-(Ph2PE)-6-(Ph2P)C6H3SiMe2](+) (6b, E = S, not isolated; 6c, E = Se, not isolated), the O,C,S-supported silyl cation [2-(Ph2PS)-6-(Ph2PO)C6H3SiMe2](+) (7, counterion B(C6F5)(4)(-)) as well as the E,C,Au-supported silyl cations [2-(Ph2PAuC6F5)-6-(Ph2PE)C6H3SiMe2](+) (8b, E = S, counterion [B{3,5-(CF3)(2)C6H3}(4)](-); 8c, E = Se, [B{3,5-(CF3)(2)C6H3}(4)](-)) using Br-2, O-2, S-8, (tht)AuC6F5, Ph3C[B(C6F5)(4)] and Ph3C[B{3,5-(CF3)(2)C6H3}(4)]. All compounds were characterized by multinuclear (H-1, C-13, F-19, Si-29, P-31, Se-77) NMR spectroscopy, ESI MS spectrometry and X-ray crystallography (2, 3a center dot H2O, 3b, 3c, 4b, 5a, 5c, 7, 8b, 8c). The gas phase structures of 2, 3a-c, 5a-c (fully optimized) and 8b, 8c (single-point calculations) were studied at the B3PW91/6-311+G(2df,p) level of theory. A set of real-space bonding indicators (RSBIs) derived from the theoretically calculated electron and pair densities were analyzed utilizing the atoms-in molecules (AIM) and electron-localizability indicator (ELI-D) space partitioning schemes.

OLED technology beyond small or expensive devices requires light-emitters, luminophores, based on earth-abundant elements. Understanding and experimental verification of charge transfer in luminophores are needed for this development. An organometallic multicore Cu complex comprising Cu–C and Cu–P bonds represents an underexplored type of luminophore. To investigate the charge transfer and structural rearrangements in this material, we apply complementary pump-probe X-ray techniques: absorption, emission, and scattering including pump-probe measurements at the X-ray free-electron laser SwissFEL. We find that the excitation leads to charge movement from C- and P- coordinated Cu sites and from the phosphorus atoms to phenyl rings; the Cu core slightly rearranges with 0.05 Å increase of the shortest Cu–Cu distance. The use of a Cu cluster bonded to the ligands through C and P atoms is an efficient way to keep structural rigidity of luminophores. Obtained data can be used to verify computational methods for the development of luminophores., Nature Communications, 11 (1), ISSN:2041-1723

In the family of metallocenes, MgCp*2 (Cp* = pentamethylcyclopentadienyl) exhibits a regular linear sandwich structure, whereas CaCp*2 is bent in both the gas phase and solid state. Bending is typically observed for metal ions which possess a lone pair. Here, we investigate which electronic differences cause the bending in complexes lacking lone pairs at the metal atoms. The bent gas-phase geometry of CaCp*2 suggests that the bending must have an intramolecular origin. Geometry optimizations with and without dispersion effects/d-type polarization functions on MCp2 and MCp*2 gas-phase complexes (M = Ca, Mg) establish that attractive methyl···methyl London dispersion interactions play a decisive role in the bending in CaCp*2. A sufficient polarizability of the metal to produce a shallow bending potential energy curve is a prerequisite but is not the reason for the bending. Concomitant ligand-induced charge concentrations and localizations at the metal atoms are studied in further detail, for which real-spac...

The oxidation of phenoxatellurine (PT) with conc. H2SO4 was reinvestigated. Two crystalline products, namely [PT2][H3O](SO4H)3 (1) and [PT](SO4) (2) were isolated and fully characterized by X-ray crystallography. The structure of 1 features [PT2]2+ dications giving rise to double-decker structures with two parallel PT layers that arise from dimerisation of two radical cations [PT]˙+. The [PT2]2+ dications and the hydrogensulfate ions are associated via secondary Te···O interations. The oxonium ion and the hydrogensulfate ions are involved in hydrogen bonding. The structure of 2 comprises ion pairs consisting of [PT]2+ dications and sulfate ions, which form a 2D coordination polymer. In addition, adjacent sulfate ions in the crystal lattice bind to tellurium atoms via secondary secondary Te···O interations.