A structurally authenticated series of chalcogenophosphinites, R2P­(ChPh) (Ch = S, Se, Te), supported by a compact tetrasilaphosphacyclopentane backbone, is presented. The parent secondary phosphane is obtained in two scalable steps from a dichlorohexasilane via substitution with 2.0 eq. NaPH2 and intramolecular ring-closure driven by PH3 elimination. Selective deprotonation furnishes lithium and potassium phosphides that serve as versatile entry points to functionalization. Reaction of the parent phosphane with PhChChPh (Ch = S, Se) yields the thio- and selenophosphinites, whereas employing the potassium phosphide delivers the full S/Se/Te series in higher yields and provides access to the tellurium derivative that is not accessible from the secondary phosphane. Across the series, 31P NMR shifts move markedly upfield in a nonlinear fashion (S → Se → Te), and UV/vis spectra exhibit progressive bathochromism; both trends are reproduced by DFT/TD-DFT and traced to HOMO–LUMO gap narrowing together with increasing polarizability and heavy-atom effects down the group. Single-crystal X-ray data reveal systematic lengthening of P-Ch bonds and widening of Si–P–Ch angles. Together, these results provide a sterically constant platform that enables direct S/Se/Te comparison and illuminates periodic trends in neutral chalcogenophosphinites stabilized by an oligosilane backbone.

In this study, we report the isolation and structural characterization of a novel 1,3-diphospha-2,4,5-trisila[1.1.1] propellane. Targeting the synthesis of di(1-naphtyl)silicon diphosphane, (1-naphtyl)2SiCl2 was reacted with NaPH2 via a classical salt metathesis route. The reaction yielded the expected diphosphanyl product ((1-naphtyl)2Si(PH2)2) alongside a second, mixed species, as indicated by multinuclear NMR spectroscopy. Attempts to selectively isolate and functionalize di(1-naphtyl)silicon diphosphane proved challenging due to its instability under standard deprotonation conditions, probing different reagents. Systematic investigations into cyclization strategies revealed that the presence of sodium phosphide is crucial for promoting PH3 evolution, which in turn drives the formation of the propellane core - likely by facilitating key deprotonation steps or stabilizing reactive intermediates. This process ultimately leads to the formation of the title compound, a 1,3-diphospha-2,4,5-trisila [1.1.1]propellane, whose cage-like structure was unambiguously confirmed by single-crystal X-ray diffraction. Preliminary reactivity tests indicate an unexpected inertness toward typical oxidative, Lewis acidic, and coordination-based conversions.

Metalloid tin clusters represent an intriguing class of compounds that bridge molecular chemistry and the solid state, yet access to diverse examples remains limited. Herein, we present a mild, modular hydrostannolysis-type strategy that enables the synthesis of tin-based clusters stabilized by fairly small tert-butyl substituents, thereby overcoming the ligand-imposed structural limitations of established methodologies. The approach gave access to a series of clusters of different core sizes, including Sn11tBu12, featuring a [1.1.1]propellane-type backbone, as well as larger Sn15tBu14 and Sn16tBu16 derivatives adopting α-Sn-like core motifs with chair arrangement reminiscent of the diamond-type structure. Experimental characterization (X-ray crystallography and 119Sn Mössbauer spectroscopy) and computational analyses (NBO and QTAIM) corroborate near-zero charges at the apical tin centers; the frontier orbitals show pronounced multicenter character across the tin framework, and several deeper-lying orbitals exhibit "superatom"-like character. Additionally, this synthetic protocol also afforded a unique, heterobimetallic Sn/Pb spiro compound, revealing the compatibility of the method with multiple group 14 elements.

Porphyrins, known for their extensive biological functions, have been adapted for diverse applications through modification of their substitution patterns and metal centers. This study focuses on synthesizing tin porphyrins with germyl- and silyl-alkenyl substituents, addressing gaps in structural characterization and solubility behavior. Additionally, their potential in bulk-heterojunction solar cells is investigated. The synthetic pathways for these porphyrins are established, and their structural properties are analyzed using single crystal X-ray diffraction. The solubility of the synthesized porphyrin (5) is compared with meso-tetraaryl and meso-tetraalkyl free-base porphyrins. Electrochemical properties are studied through cyclic voltammetry, and density functional theory (DFT) calculations provide insights into the highest occupied and lowest unoccupied molecular orbitals. Despite promising optical and electrochemical properties, the solar cell performance of the synthesized porphyrins remains moderate, highlighting the need for further functionalization to enhance the power conversion efficiency.

Controlled insertion into a single P-P bond of white phosphorus (P4) was achieved by employing a diaryl stabilized stannylene, Ar*2Sn (Ar*=2,6-bis(benzhydryl)-4-iPr-phenyl). Conversions of the stannylene with P4 gave a non-pyrophoric, air-stable storage compound, which releases P4 quantitively upon irradiation with light (354 or 455 nm). Alternatively, the phosphorus cage is detached by reacting the storage compound with PhChChPh (Ch=Se, Te). Despite the recent advances in the directed conversion of P4 using main group element compounds, Ar*2Sn constitutes only the second structurally characterized example of a stannylene capable of performing controlled, reversible addition and release of white phosphorus.

Insertion of a nitrogen atom modifies the electronic structures and photochemistry of polycyclic aromatic hydrocarbons by introducing nπ* states into the molecules. To better understand the electronic structures of isolated polycyclic aromatic nitrogen-containing hydrocarbons (PANHs) and their dimers as well as the influence of the position of the nitrogen atom in the molecule, we investigate three different azaphenanthrenes, benzo[f]quinoline, benzo[h]quinoline, and phenanthridine, in a joint experimental and computational study. Experimentally, resonance-enhanced multiphoton ionization (REMPI) spectroscopy is applied to characterize the excited electronic states. The REMPI spectra of the azaphenanthrene monomers have a rather similar appearance, with origins between 3.645 and 3.670 eV for the 1ππ* ← S0 transition. In contrast to the phenanthrene parent, 2ππ* ← S0 is broad and unstructured even at the band origin. The experiments are accompanied by density functional theory computation, and vibrationally resolved spectra are simulated using a time-independent approach. The differences between phenanthrene and the azaphenanthrenes are assigned to perturbations due to the low-lying 1(nπ*) state, which accelerates nonradiative deactivation. For the dimers, it is found that two π-stacked isomers with two electronic transitions each contribute to the electronic spectrum, leading to overlapping bands that are difficult to assign.

In this contribution, we present the synthesis of two groups of novel acylsilanes 1-6. Compounds 1 and 2 represent tris(trimethoxysilyl)acylsilanes, and compounds 3-6 are 1,4-tetrakis(silyl)-1,4-bisacylsilanes. All isolated compounds were characterized by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy and X-ray crystallography. Additionally, these compounds were further analyzed by ultraviolet/visible (UV/vis) spectroscopy and their longest wavelength absorption bands were assigned by density functional theory (DFT) calculations. On the basis of the well-known Brook rearrangement of acylsilanes, we irradiated 1-6 in benzene solutions at 405 nm (λ) for several hours. Photolysis of compounds 1 and 2 afforded the same silene rearrangement products as found in previous investigations of structurally related acylsilanes. In addition, trapping experiments with MeOH further support our proposed mechanism for silene formation. The photolysis of tetrakis(trimethylsilyl)bisacylsilane 3 gave rise to the formation of a monosilene intermediate 10; upon prolonged irradiation, the subsequently formed bissilene undergoes a fast dimerization to bicyclic product 11. Interestingly, unlike the expected head-to-head dimerization of Brook-type silenes, this bissilene undergoes a selective head-to-tail dimerization. In contrast, tetrakis(trimethylsilyl)bisacylsilane 4 undergoes a selective and completely stereoselective double CH activation to air stable bicyclic system 12. The mechanism of this rearrangement is fully described by DTF calculations. Unfortunately, tetrakis(trimethoxysilyl)bisacylsilanes 5 and 6 underwent unselective photochemical rearrangements.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Imidazole-2-thiones have attracted considerable interest in the past as materials for potential applications in the pharmaceutical and chemical industries. Herein, the synthesis of a series of backbone silylated 1,3-dialkylimidazol-2-thiones is reported. The developed synthesis protocol involves the silylation of N,N-dimethylimidazol-2-thione 1 followed by the addition of organochlorosilanes RnSiCl4-n (R=Me, Ph; n=0-4) and enabled the synthesis of the C-silylated derivatives with monocyclic, silyl-bridged or fused tricyclic structures. Reactivity studies performed with N,N-dimethyl-4,5-bistrimethylsilylimidazole-2-thione as a model substance showed surprisingly stable silicon-vinyl bonds and reactivity patterns closely related to those observed for the unsilylated species 1. Combined UV-spectroscopic and computational studies revealed only minor impact of the silyl substituents on the electronic structure of the imidazol-2-thione ring.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

In continuation of our recent studies on group 14 rings with exocyclic silicon-carbon double bonds, we report here on the synthesis and reactivity of previously unknown acyl-substituted 1,4-disilacyclohexa-2,5-dienes. 1,1,4,4-Tetrakistrimethylsilyl-1,4-disilacyclohexa-2,5-diene 1 cleanly afforded the silyl anion 1-K after addition of 1 equiv of KO t Bu. 1-K subsequently could be reacted with various electrophiles to the expected substitution products including compounds 4 and 5. When photolyzed with λ > 300 nm radiation, 4 and 5 undergo Brook-type 1,3-Si → O migration reactions to generate the corresponding 1,4-disilacyclohexadienes with exocyclic Si=C bonds as the primary products. These metastable silenes only could be characterized in form of appropriate quenching products. The reaction of compound 4 with KO t Bu followed by the addition of 1 equiv of PhMe2SiCl surprisingly gave the silylated 1,4-disilanorbornadiene cages 8 and 9 instead of the expected exocyclic silene. The responsible sila-Peterson-type mechanism could be elucidated by density functional theory calculations at the conductor-like polarizable continuum model (THF) B3LYP-GD3/6-31 + G(d) level and by the isolation and characterization of unstable intermediate products after proper derivatization.

Abstract A series of non‐fullerene acceptors based on perylene monoimides coupled in the peri position through phenylene linkers were synthesized via Suzuki‐coupling reactions. Various substitution patterns were investigated using density functional theory (DFT) calculations in combination with experimental data to elucidate the geometry and their optical and electrochemical properties. Further investigations of the bulk properties with grazing incidence wide angle X‐ray scattering (GIWAXS) gave insight into the stacking behavior of the acceptor thin films. Electrochemical and morphological properties correlate with the photovoltaic performance of devices with the polymeric donor PBDB‐T and a maximum efficiency of 3.17 % was reached. The study gives detailed information about structure–property relationships of perylene‐linker‐perylene compounds.

From conversions of Ar2SnH2 (Ar = Tripp, Dipp; Tripp = 2,4,6-Triisopropylphenyl, Dipp = 2,6-Diisopropylphenyl), and a bismuth(III) amide, Bi[N(SiMe3)2]3, we isolated the first representatives of mixed, uncharged Bi/Sn clusters, Bi8Sn3Ar6. Along with unprecedented bicyclo[2.2.0]hexanes, (HAr2Sn)2Sn2Bi4, these have been characterized by single crystal X-Ray diffraction, heteronuclear NMR, vibrational and UV-Vis spectroscopy. Quantum-chemical calculations were carried out in order to understand bonding within the isolated polyhedral compounds.

The novel diphosphatrisilanes {(R 2 P‐Si(SiMe 3 ) 2 ‐) 2 ‐SiMe 2 } [R = Ph, H] and the cyclophosphatrisilabutanes {R–PSi 3 } [R = H, SiMe 3 ] have been prepared via salt metathesis reactions between phosphanides and 2,4‐dihalogenated pentasilanes and characterized via NMR spectroscopy. The experimental results were supported by DFT calculations. Although P–Si bond formation was observed in all cases, the outcome of the reactions varied depending on the nature of ligands on the phosphanides, forming either linear diphosphatrisilanes or cyclic phosphatrisilacyclobutanes. DFT studies were performed to get a better understanding of the reactions. The precursor silanes were fully characterized using NMR spectroscopy and single‐crystal X‐ray diffraction and offer interesting building blocks. In addition, a modified route for the synthesis of P(TMS) 3 was successfully carried out, achieving high yields of up to 73 %, circumventing the use of white phosphorus and phosphine gas during the reaction.

The reaction of diphenyltin dihydride with LiAlH4 gives access to a set of charged tin cages as their lithium salts. Variation in the ratio of reactants provides a perstannabicyclooctane dianion and a perstannanorbornane as the di- and monoanions. These compounds can be synthesised selectively by careful stoichiometric control and have been characterised by single crystal X-ray diffractometry, NMR and UV-vis spectroscopy. Computational exploration of the electronic structures of these compounds was undertaken and, in agreement with structural and spectroscopic features, indicated significant σ-delocalisation in the tin skeletons.

The factors affecting the stabilization of diphosphastannylenes, such as substituent size, steric demand, and type of substituent (aryl, alkyl, silyl) were investigated via a comprehensive DFT and experimental investigation. The influence of various substituents (H, Me, tBu, Ph, TMS, Hyp = (Si(SiMe3)3)) on the pyramidalization of the phosphorus centers and cone angle determination of those substituents were carried out. Through these considerations, ligand systems capable of isolating a stable Sn(II) species were determined. Synthetic work led to the isolation of dimeric supermesityl(trimethylsily)phosphanides, 2,4,6-tris(t-butyl)phenyl trimethylsilyl lithium phosphanide, 2,4,6-tris(t-butyl)phenyl trimethylsilyl potassium phosphanide, and one hypersilylphosphanide [HypP(SiMe3)K·DME]. In addition to that, a novel monomeric diphosphastannylene [HypP(SiMe3)]2Sn was isolated as well as confirmed by experimental and calculated NMR data and single crystal X-ray analysis.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.