1,2,4‐Diazaphospholide Complexes of Tin(II): From Nitride Stannylene to Stannylenated Ammonium Ions

Abstract

Tin knows its oniums! An unusual nitride tetrastannylene and a stannylenated ammonium ion stabilized by a samarium tetradiazaphospholido counterion are the first examples of a tris(organostannylenyl)amine derivative and a divalent tin coordinate onium ion that incorporates 1,2,4‐diazaphospholide ligand (see figure).magnified image

Germanium and Tin Monoxides Trapped by Oxophilic Germylene and Stannylene Ligands

“…The 31 P{ 1 H} NMR spectrum of 3 exhibited two sharp singlets at δ 84.73 and 82.89 ppm, which are comparable to the sharp singlets reported for the nitride stannylene [(η 1 :η 1 (N,N)-tBu 2 dp)(η 1 (N)-tBu 2 dp) 2 (μ 3 -Sn) 2 (μ 4 -N)(μ 3 -Sn) 2 (η 1 :η 1 (N,N)-tBu 2 dp) 2 ] (δ 81.6, 97.1 ppm). 12 A significant upfield resonance was detected in the 119 Sn{ 1 H} NMR spectrum at δ −742 ppm, similar to the resonance at δ −720 ppm displayed for the dimeric pyrazolato stannylene [{Sn(η 1 -3,5-(CF 3 ) 2 pz) 2 } 2 ], 22 indicating that the tin(II) center is in a uniform environment. 23 Attempts to obtain single crystals of 2 in high enough quality for X-ray crystal diffraction analysis have so far been unsuccessful, but preliminary structural investigations showed that 2 has structural characteristics similar to those of 3.…”

“…24,25 The slipped η 2 (N,N)-1,2,4-diazaphospholide would best be described as a monodentate ligand 26 S3 and S4 in the Supporting Information) and its discussion are given in the Supporting Information. 20 Stannylenes stabilized by azolyl derivatives predominantly adopt the η 1 or η 1 :η 1 form, 12,22 but 3 is the first example of a group 14 element compound in such an edge-bound, slipped η 2 mode.…”

“…This prompted us to explore the potential for capturing molecular SnO or even the lighter congener of GeO utilizing non-pincer ligands. In this context, we used the monoanionic 3,5-di- tert -butyl-1,2,4-diazaphospholide ligand ([3,5- t Bu 2 dp] − ) ( 1 – ) − to prepare the 1,2,4-diazaphospholide-based germylene and stannylene M­[η 2 ( N , N )-3,5- t Bu 2 dp] 2 (M = Ge ( 2 ), Sn ( 3 )) as molecular traps. Treating hydrolyzed Ge­[N­(SiMe 3 ) 2 ] 2 and Sn­[N­(SiMe 3 ) 2 ] 2 with 2 and 3 , respectively, resulted in the complex M­(μ-O)­[M­{η 1 ( N )-(3,5- t Bu 2 dp)} 2 ] 2 (M = Ge ( 4 ), Sn ( 5 )), which contained the formally trapped MO (M = Ge, Sn) moiety.…”

1,2,4-Diazaphospholide complexes of lanthanum(iii), cerium(iii), neodymium(iii), praseodymium(iii), and samarium(iii): synthesis, X-ray structural characterization, and magnetic susceptibility studies

“…In summary, by modifying the sterics and electronics of the ligands and by modulating the lanthanide ion, a few of novel heteroleptic, charge-separated heterobimetallic, and polymeric alkali metal ate complexes of 1,2,4-diazaphospholide lanthanum(III), cerium(III), neodymium(III), praseodymium(III), and samarium(III) (3)(4)(5)(6)(7)(8)(9)(10)(11)(12) were readily synthesized via the metathesis reaction of MCl 3 ⋅(THF) m (m = 1-2) and 3,5-di-substituent-1,2,4-diazaphospholide K[3,5-R 2 dp] in a varied ratio at room temperature in tetrahydrofuran. Our work therefore demonstrated that an extensive 1,2,4-diazaphoshpholide rare earth metal complexes could be accessible by this path.…”

“…5 Owing to the presence of two very different binding sites, mixed P,N-1,2,4-diazaphospholide ligands possess unusual electronic properties 5 that potentially make them very attractive in both coordination chemistry and catalysis. [5][6][7][8] Recently, the preparation of novel charge-separated heterobimetallic, or -alkali metal ate lanthanide complexes 10a-b bearing 1,2,4-diazaphospholide ligands 5a have attracted our attention because such complexes are expected to be potential effective catalysts in varied organic transformations, 10c-f precursors for low-valent rare earth metal complex, 10g-h magnetic materials, 10h-l transition metal-lanthanide coordination complexes, 10m-o and molecule magnets. The unique electronic properties of 1,2,4-diazaphospholides allow them to form complexes with novel molecular structural characteristics, with the coordination types η 1 (N), η 1 (N1):η 1 (N2), and η 2 (N1,N2) via the nitrogen atom or atoms and type η 5 via the π-electron system of the ring.…”