0000000000129565
AUTHOR
Dana Eisler
Syntheses and Structures of Magnesium and Zinc Boraamidinates: EPR and DFT Investigations of Li, Mg, Zn, B, and In Complexes of the [PhB(NtBu)2]•- Anion Radical
The first magnesium and zinc boraamidinate (bam) complexes have been synthesized via metathetical reactions between dilithio bams and Grignard reagents or MCl2 (M = Mg, Zn). The following new classes of bam complexes have been structurally characterized: heterobimetallic spirocycles {(L)μ-Li[PhB(μ-NtBu)2]}2M (6a,b, M = Mg, L = Et2O, THF; 6c, M = Zn, L = Et2O); bis(organomagnesium) complexes {[PhB(μ3-NtBu)2](MgtBu)2(μ3-Cl)Li(OEt2)3} (8) and {[PhB(μ3-NtBu)2](MgR)2(THF)2} (9a, R = iPr; 9b, R = Ph); mononuclear complex {[PhB(μ-NDipp)2]Mg(OEt2)2} (10). Oxidation of 6a or 6c with iodine produces persistent pink (16a, M = Mg) or purple (16b, M = Zn) neutral radicals {Lx-μ-Li[PhB(μ-NtBu)2]2M}• (L …
An Unusual Ditelluride: Synthesis and Molecular and Electronic Structures of the Dimer of the Tellurium-Centered Radical [TePiPr2NiPr2PTe]•
Facile formation of the ditelluride [(TePiPr2NiPr2PTe-)2], which exists as a centrosymmetric dimer (see picture: Te green, P purple, N blue, C gray) with a weak Te[BOND]Te bond, embodies a new feature of the chemistry of dichalcogenoimidodiphosphinate ligands. The monotelluride HPiPr2NiPr2PTe analogue is obtained as the P[BOND]H tautomer. peerReviewed
Stable spirocyclic neutral radicals: aluminum and gallium boraamidinates
Stable dark red (M = Al) or dark green (M = Ga) neutral radicals {[PhB(μ-NtBu)2]2M}˙ are obtained by the oxidation of their corresponding anions with iodine, and EPR spectra supported by DFT calculations show that the spin density is equally delocalized over all four nitrogen atoms in these spiroconjugated systems. peerReviewed
Experimental and Theoretical Investigations of Structural Isomers of Dichalcogenoimidodiphosphinate Dimers: Dichalcogenides or Spirocyclic Contact Ion Pairs?
A synthetic protocol for the tert-butyl-substituted dichalcogenoimidodiphosphinates [Na(tmeda){(EPtBu2)2N}] (3 a, E=S; 3 b, E=Se; 3 c, E=Te) has been developed. The one-electron oxidation of the sodium complexes [Na(tmeda){(EPR2)2N}] with iodine produces a series of neutral dimers (EPR2NPR2E[BOND])2 (4 b, E=Se, R=iPr; 4 c, E=Te, R=iPr; 5 a, E=S, R=tBu; 5 b, E=Se, R=tBu; 5 c, E=Te, R=tBu). Attempts to prepare 4 a (E=S, R=iPr) in a similar manner produced a mixture including HN(SPiPr2). Compounds 4 b, 4 c and 5 a–c were characterised by multinuclear NMR spectra and by X-ray crystallography, which revealed two alternative structures for these dimeric molecules. The derivatives 4 b, 4 c, 5 a an…
New tellurium-containing ring systems
The recent discovery of a suitable synthesis of the monoanionic ditelluroimidodiphosphinate ligands [TePR2NPR2Te]− (R = Ph, iPr, tBu) has facilitated investigations of the fundamental chemistry of these chelating inorganic ligands. This article is focused on aspects of that chemistry in which the behaviour of this ditelluro PNP ligand differs from that of the well-studied dithio and diseleno congeners. The emphasis is on new tellurium-containing ring systems formed in: (a) redox transformations and (b) the synthesis of metal complexes. peerReviewed