Synthesis of chelating diamido Sn(iv) compounds from oxidation of Sn(ii) and directly from Sn(iv) precursors

Abstract

Three dimethyltindiamides containing chelating diamide ligands were synthesised from the reaction of the dilithiated diamine and Me2SnCl2; [SnMe2(L1)] 1 (L1 = κ(2)-N(Dipp)C2H4N(Dipp)), [SnMe2(L2)] 2 (L2 = κ(2)-N(Dipp)C3H6N(Dipp)) and [SnMe2(L3)] 3 (L3 = κ(2)-N(Dipp)SiPh2N(Dipp)), Dipp = 2,6-(i)Pr2C6H3. Reaction of (L2)H2 with SnCl4 and NEt3 led to the formation of the diamidotin dichloride [SnCl2(L2)] 4 whereas reaction of (L1)H2 with SnCl4 and NEt3, or [Sn(L1)] with SnCl4, led to the exclusive formation of the amidotin trichloride [SnCl3{κ(2)-DippN(H)C2H4N(Dipp)}] 5. Reactions of [Sn(L1)] with sulfur and selenium formed [{Sn(L1)(μ-E)}2] (E = S 10 and Se )11. MeI reacted with N-heterocyclic stannylenes to generate the Sn(iv) addition products [Sn(Me)I(L1)] 12, [Sn(Me)I(L2)] 13, [Sn(Me)I(L3)] 14 and [Sn(Me)I(L4)] 15 (L4 = κ(3)-N(Dipp)C2H4OC2H4N(Dipp)), and subsequent reaction with AgOTf (OTf = OSO2CF3) generated the corresponding Sn(iv) triflates [Sn(Me)OTf(L1)] 16, [Sn(Me)OTf(L2)] 17 and [Sn(Me)OTf(L4)] 19 with [Sn(Me)OTf(L3)] 18 formed only as a mixture with unidentified by-products. All of the compounds were characterised by single crystal X-ray diffraction.

Cyclic Four‐Membered Stanna Thio and Seleno Compounds from 2‐Aminopyridinato Stannylenes

“…The 119 Sn NMR resonances for 3 appears at δ = –262.5 which falls within the range of [CyNC(Me)NCy] 2 Sn (– 272.0 ppm) and [CyNC( t Bu)NCy] 2 Sn (–223.0 ppm)[11e] and for 4 it is at δ = –124.1 ppm which is in the close proximity of the previously reported heteroleptic Sn(II) amido guanidinates. [12f] The molecular structures of 3 and 4 are determined by single‐crystal X‐ray studies, which reveal the presence of four‐coordinated Sn atom (Figure and Figure ). The small angles of the aminopyridinato four‐membered rings ( 3 : 57.6(2) and 58.4(2)°; 4 : 58.24(7) and 57.96(7)°) led to the distortion of the four‐membered rings and the Sn atom can be best described as distorted square pyramid considering the lone pair on Sn in 3 and 4 .…”

“…Synthesis of tin chalcogenides complexes via the reaction of stannylenes with elemental chalcogen has shown distinct bonding, which includes the formation of Sn=E (E = S, Se, Te) double bonds when the substituents on tin are bulky . However, the decrease in the bulkiness of the aryl substituents on tin results in the formation of bridging Sn‐E‐Sn moiety or four membered Sn 2 E 2 species …”

One-Pot Synthesis of Heavier Group 14 N-Heterocyclic Carbene Using Organosilicon Reductant

“…This arises due to the thermolabile nature of NHSn [24,25], leading to difficulties in acquiring NMR data ( Figures S8 and S9). The presence of additional peaks in the 119 Sn NMR ( Figure S10) of the reaction mixture may be attributed to the formation of Sn(IV) compounds [26,27]. Single crystals of compound 2 were obtained from hexane extract at −40 °C in a yield of 35% (Figures S11-S13 and S24, Table S2).…”

Synthesis and crystal structures of antimony(III) and tin(IV) compounds with an amino-amido-silane ligand

“…The Si-N bonds in bis(amino)silanes are rather strong, while it is desirable to attach bulky R groups to the silicon and nitrogen atoms to achieve increased kinetic stability of the metal complexes [4]. Recently, series of metal complexes featuring sterically encumbered bis(amido)silane ligands have been reported, such as [Me 2 -Si(NDipp) 2 SbCl] (Dipp = 2,6-i Pr 2 C 6 H 3 ) [5], [Me 2 Si(NDipp) 2 BiCl] [6] and [Ph 2 Si(NDipp) 2 SnMe 2 ] [7]. These compounds with a variety of backbones were prepared by the salt metathesis reaction of the appropriate dilithiated diamide with metal chloride.…”