MeSi(CH2 SnRO)3 (R=Ph, Me3 SiCH2 ): Building Blocks for Triangular-Shaped Diorganotin Oxide Macrocycles

Synthesis of bi- and tetradentate poly-Lewis acids by hydroalumination of poly-alkynyl-anthracene derivatives

Photo-dimers of 1,5-diethynylanthracene and 1,5-bis[(trimethylsilyl)ethynyl]anthracene, obtained by UV radiation of the monomers, were treated with the bulky aluminium hydride [(SiMe₃)₂HC]₂AlH in hydroalumination reactions. Hydroalumination of the tetraethynyl-substituted anthracene photo-dimers (syn and anti) led to fourfold aluminium-functionalized Janus-like products with two aluminium functions on each side oriented towards the same direction. The reactions of the monomeric anthracene derivatives with [(SiMe₃)₂HC]₂AlH afforded semi-flexible bidentate Lewis acids, which are interesting building blocks for molecular chains bearing multiple Lewis-acidic functions. The aluminium-functionalized anti-photo-dimer was treated with various donor molecules to gain insight into its host-guest chemistry. All poly-Lewis acids and their adducts were characterized by X-ray diffraction experiments, multinuclear NMR spectroscopy and by elemental analyses.

Cluster-Glass for Low-Cost White-Light Emission

The development of efficient and high-brilliance white-light sources is an essential contribution to innovative emission technologies. Materials exhibiting strong nonlinear optical properties, in particular second-harmonic generation (SHG) or white-light generation (WLG), have therefore been investigated with great activity in recent times. While many new approaches have been reported until now, the processability of the compounds remains a challenge. Here, a new class of materials, denoted as "cluster-glass", which do not only show superior white-light emission properties upon irradiation by an inexpensive continuous-wave infrared laser diode, but can be easily accommodated in size and shape by formation of robust glassy solids, is introduced. The cluster-glass materials are fabricated by mild heating from crystalline powders of adamantane-type clusters exhibiting a quaternary, inorganic-organic hybrid cluster core [(PhSi)(CH₂ )₃ (PhSn)E₃ ] (E  =  S, Se, Te). The process is fully reversible and preserves the integrity of the clusters in the glass, as proven by solution spectroscopy and recrystallization. Theoretical studies corroborate the importance of the quaternary nature of the cluster cores for the observed structural and optical phenomena. Thanks to these findings, high-brilliance white-light sources can be synthesized in form of stable, robust glass of any shape, which ultimately renders them suitable for everyday's applications.

Organic-Inorganic High-Valence Sn18-oxo Clusters: Direct Utilization of an Inorganic Sn(IV) Source to Improve the Nuclearity and Electrocatalytic CO2 Reduction Properties

The high-valence tin-oxo clusters are of great significance because of their structural diversity and potential applications in many fields, e.g., catalysis, extreme ultraviolet (EUV) lithography, and so on. The synthesis of high-nuclearity tin-oxo clusters remains a great challenge currently, since the key inorganic Sn_xO_y core with Sn⁴⁺ ions could not be obtained only by the in situ Sn-C bond cleavage in organic tin sources. In this context, we synthesize three organic-inorganic hybrid Sn₁₈-oxo clusters, [(BuSn)₁₂Sn₆(μ₃-O)₂₀(ba)₁₂(PhPO₃)₄] (Bu = butyl, Hba = benzoic acid), [(BuSn)₁₂Sn₆(μ₃-O)₂₀(pmba)₁₂(PhPO₃)₄]·2CH₃CN·2H₂O (Hpmba = p-toluic acid), and [(BuSn)₁₂Sn₆(μ₃-O)₂₀(ptba)₁₂(PhPO₃)₄]·2CH₃CN·2iPrOH·2H₂O (Hptba = p-tert-butyl benzoic acid), as well as one Sn₆-oxo cluster [(BuSn)₆(μ₃-O)₂(μ₂-OH)₄(pnba)₆(PhPO₃)₂] (Sn₆) (Hpnba = p-nitrobenzoic acid) by combining an inorganic precursor (SnCl₄) with an organic one (butyltin hydroxide oxide). It is shown that an inorganic dicyclo-chain-like Sn₆O₈ core encapsulated in a U-shaped dodecanuclear butyltin-oxo ring plays an important role in the construction of Sn₁₈-oxo clusters and that the use of a ligand with an electron-withdrawing group reduces the nuclearity of clusters to Sn₆. Moreover, electrocatalytic CO₂ reduction studies confirm that the electrocatalytic activities of the Sn₁₈ clusters are superior to those of the Sn₆ cluster, probably due to the hybrid organotin-inorganotin structures. Our work not only opens a new way for constructing high-nuclearity tin-oxo clusters but also is helpful in deeply revealing the structure-properties relationship of tin-oxo clusters.

Construction and two-dimensional assembly of double-shell Na@Sn6L6@Sn3L3 clusters through tetrahedral citrate ligands

Herein we report a double-shell Na@Sn6L6@Sn3L3 cluster and their further assembly into 2D layer, which belongs to rare Sn-oxo coordination cage based extended structure. Tetrahedral citrate ligands with multiple coordination...

Selective replacement of organosilicon units in the cluster [(PhSi)4S6] with coinage metal complex fragments

Adamantane-type organo-group 14 chalcogenide clusters were shown to possess extreme non-linear optical properties. Reactivity studies of corresponding organosilicon sulfide clusters towards copper and silver complexes indicate a replacement of exactly one of the organosilicon groups with a metal complex fragment to form [(Et₃PAg)₃(PhSi)₃S₆] (1) and [Na₂(thf)_2.33][(Me₃PCu)(PhSi)₃S₆] (2)-in striking contrast to reactions of organotin chalcogenide clusters, which are more significantly and less systematically re-organized. The silicon compounds are thus more suited for controlled modifications of their geometric and electronic structures.

Molecular Cage Assembly by Sn-O-Sn Bridging of Di-, Tri- and Tetranuclear Organotin Tectons: Extending the Spacing in Double Ladder Structures

Hydrolysis reactions of di‐ and trinuclear organotin halides yielded large novel cage compounds containing Sn−O−Sn bridges. The molecular structures of two octanuclear tetraorganodistannoxanes showing double‐ladder motifs, viz., [{Me₃SiCH₂(Cl)SnCH₂YCH₂Sn(OH)CH₂SiMe₃}₂(μ‐O)₂]₂ [1, Y=p‐(Me)₂SiC₆H₄‐C₆H₄Si(Me)₂] and [{Me₃SiCH₂(I)SnCH₂YCH₂Sn(OH)CH₂SiMe₃}₂(μ‐O)₂]₂⋅0.48 I₂ [2⋅0.48 I₂, Y=p‐(Me)₂SiC₆H₄‐C₆H₄Si(Me)₂], and the hexanuclear cage‐compound 1,3,6‐C₆H₃(p‐C₆H₄Si(Me)₂CH₂Sn(R)₂OSn(R)₂CH₂Si(Me)₂C₆H₄‐p)₃C₆H₃‐1,3,6 (3, R=CH₂SiMe₃) are reported. Of these, the co‐crystal 2⋅0.48 I₂ exhibits the largest spacing of 16.7 Å reported to date for distannoxane‐based double ladders. DFT calculations for the hexanuclear cage and a related octanuclear congener accompany the experimental work.

MeSi(CH2 SnRO)3 (R=Ph, Me3 SiCH2 ): Building Blocks for Triangular-Shaped Diorganotin Oxide Macrocycles

The syntheses of the novel silicon-bridged tris(tetraorganotin) compounds MeSi(CH2 SnPh2 R)3 (2, R=Ph; 5, R=Me3 SiCH2 ) and their halogen-substituted derivatives MeSi(CH2 SnPh(3-n) In )3 (3, n=1; 4, n=2) and MeSi(CH2 SnI2 R)3 (6, R=Me3 SiCH2 ) are reported. The reaction of compound 4 with di-t-butyltin oxide (t-Bu2 SnO)3 gives the oktokaideka-nuclear (18-nuclear) molecular diorganotin oxide [MeSi(CH2 SnPhO)3 ]6 (7) while the reaction of 6 with sodium hydroxide, NaOH, provides the trikonta-nuclear (30-nuclear) molecular diorganotin oxide [MeSi(CH2 SnRO)3 ]10 (8, R=Me3 SiCH2 ). Both 7 and 8 show belt-like ladder-type macrocyclic structures and are by far the biggest molecular diorganotin oxides reported to date. The compounds have been characterized by elemental analyses, electrospray mass spectrometry (ESI-MS), NMR spectroscopy, 1 H DOSY NMR spectroscopy (7), IR spectroscopy (7, 8), and single-crystal X-ray diffraction analysis (2, 7, 8).