Synthesis of Low-Valent Dinuclear Group 14 Compounds with Element-Element Bonds by Transylidation.

Dinuclear low-valent compounds of the heavy main group elements are rare species owing to their intrinsic reactivity. However, they represent desirable target molecules due to their unusual bonding situations as well as applications in bond activations and materials synthesis. The isolation of such compounds usually requires the use of substituents that provide sufficient stability and synthetic access.

Isolation of a Diylide-Stabilized Stannylene and Germylene: Enhanced Donor Strength through Coplanar Lone Pair Alignment.

The preparation of the first stable diylide-substituted stannylene and germylene (Y E, with E=Ge, Sn and Y=[PPh -C-SO Tol] ) is reported. The synthesis is easily accomplished in one step from the sulfonyl-substituted metalated ylide YNa and the corresponding ECl precursors. Y Ge and Y Sn exhibit unusual structures in the solid state and in solution, in which the three adjacent lone pairs in the C-E-C linkage are arranged coplanar to each other.

An unprecedented 1,4-diphospha-2,3-disila butadiene (-P[double bond, length as m-dash]Si-Si[double bond, length as m-dash]P-) derivative and a 1,3-diphospha-2-silaallyl anion, each stabilized by the amidinate ligand.

The first acyclic 4π-electron -P[double bond, length as m-dash]Si-Si[double bond, length as m-dash]P- motif with two four coordinate silicon substituents supported by the amidinate ligand and two coordinate phosphorus has been synthesized from the reaction of heteroleptic chlorosilylene LSiCl (1), TripPCl (Trip = 2,4,6-PrCH) and KC in a 1 : 1 : 3 ratio. The same reaction in a 1 : 2 : 6 ratio in the presence of one equivalent of 18-crown-6 ether affords the 1,3-diphospha-2-silaallyl anion.

The Structure of the Carbene Stabilized Si2H2 May Be Equally Well Described with Coordinate Bonds as with Classical Double Bonds.

The cyclic alkyl(amino) carbene stabilized Si2H2 has been isolated in the molecular form of composition (Me-cAAC:)2Si2H2 (1) and (Cy-cAAC:)2Si2H2 (2) at room temperature. Compounds 1 and 2 were synthesized from the reduction of HSiCl3 using 3 equiv of KC8 in the presence of 1 equiv of Me-cAAC: and Cy-cAAC:, respectively. These are the first molecular examples of Si2H2 characterized by single crystal X-ray structural analysis.

Insertion of Cyclic Alkyl(amino) Carbene into the Si-H Bonds of Hydrochlorosilanes.

Carbenes are known for their ability to abstract HCl from hydrochlorosilanes to form carbene hydrochloride adducts. In contrast, the Si-H bond insertion products RSiCl2(cAACH) (2, 4, 6, and 8) have been formed in the reaction of RSiHCl2 [R = Ar(SiMe3)N (1), Cp* (3), PhC(NtBu)2 (5), Cl (7); Ar = 2,6-iPr2C6H3] with a cyclic alkyl(amino) carbene (cAAC:) irrespective of the steric demand of the R group. The new products have been characterized by various analytical tools including X-ray crystallography, electron ionization mass spectrometry, and NMR spectroscopy.

A stable dimer of SiS2 arranged between two carbene molecules.

The Me-cAAC:-stabilized dimer of silicon disulfide (SiS2 ) has been isolated in the molecular form as (Me-cAAC:)2 Si2 S4 (2) at room temperature [Me-cAAC:=cyclic alkyl(amino) carbene]. Compound 2 has been synthesized from the reaction of (Me-cAAC:)2 Si2 with elemental sulfur in a 1:4 molar ratio under oxidative addition. This is the smallest molecular unit of silicon disulfide characterized by X-ray crystallography, electron ionization mass spectrometry, and NMR spectroscopy.

Assembly of hexa- and trinuclear monoorganostannoxanes: hemi-labile nature of intramolecular N→Sn coordination in RSnCl3 (R = 2-phenylazophenyl).

The reactions of RSnCl3 [R = 2-(phenylazo)phenyl] with phosphonic acids, RPO3H2 (R = t-Bu, C6H11) or (ArO)2PO2H (Ar = 4-NO2-C6H5O) in refluxing THF afforded hexatin cages, [(RSn)6(μ-OH)6(μ3-O)2(t-BuPO3)4]·5THF (1), [(RSn)6(μ-OH)6(μ3-O)2(C6H11PO3)4]·THF (2) and [(RSn)6(μ-OH)4(μ3-O)2{(NO2C6H4O)PO3}4]·THF (3), respectively. On the other hand, the reactions of RSnCl3 with 1,1,2,3,3-pentamethylene phosphinic acid [cycPO2H] or Ph2P(O)OH under similar reaction conditions afforded trinuclear O-capped clusters [(RSn)3(μ3-O) (μ2-OH)3 (μ-cycPO2)3] [cycPO2]·CH3CN·H2O (4) and [(RSn)3(μ3-O) (μ2-OH)3 (μ-Ph2PO2)3] [Ph2PO2]·CH3CN·CH2Cl2 (5) respectively. Molecular structures of 1-3 reveal that the intramolecular N→Sn coordination found in RSnCl3 is hemilabile; 1-3 do not contain such a feature and the tin atoms in these compounds are six coordinate, possessing a 1C, 5O coordination environment in a distorted octahedral geometry.

Synthesis, structure, and H2/CO2 adsorption in a three-dimensional 4-connected triorganotin coordination polymer with a lvt [corrected] topology.

A 4-connected triorganotin 3D coordination polymer in a lvt [corrected] topology has been shown to possess 1D microchannels along its crystallographic a axis. This main-group-element-containing framework structure shows selective gas adsorption, preferring CO2 and H2 over N2.