Synthesis of 2,6‐Bis(bis(2‐(methylthio)phenyl)phosphino)‐4‐methylphenol, a Novel Polydentate Ligand Containing Two Tripodal [S,S,P,O] Coordination Pockets; Crystal Structure of the Dimeric Thallium(I) Complex

Abstract

The reactions of bis(2-(methylthio)phenyl)chlorophosphine (5a) (2 equivalents) with the O-protected 2,6-dilithio-4-methylphenol followed by acidic workup led to the isolation of 2,6-bis(bis(2-(methylthio)phenyl)phosphino)-4-methylphenol (2). Analogous reactions do not proceed if the sterically bulkier bis(2-(tert-butylthio)phenyl)chlorophosphine (5b) is used instead of 5a. Compound 2 is a topological analog of binucleading ligands built on a 2,6-diaminophenol core, where two tripodal N-or Oligating compartments are flanking the phenolate functionality. A distinguishing feature of 2 is the "soft" donor environment of the potentially [S,S,P]-ligating pockets flanking the phenolic OH group. Reaction of 2 with TlOEt lead to the formation of the dimeric 1879 thallium(I) phenoxide (3), which was characterized by a single crystal X-ray diffraction study. In addition to µ-phenoxide ligation, in the solid state each thallium atom also interacts with two phosphorus atoms from the opposing ligands. The interactions are not equivalent, with the two Tl I ϪP distances differing by ca. 0.3 Å . No significant Tl···S interactions are present in the solid state. Room temperature 31 P NMR measurements indicate the dynamic behavior of 3 in solution.

o‐Hydroxyarylphosphanes: Strategies for Syntheses of Configurationally Stable, Electronically and Sterically Tunable Ambiphiles with Multiple Applications

“…HI, HBr or BBr 3 . The usefulness of this protocol was demonstrated by the synthesis of 6 (R= o ‐MeSC 6 H 4 ) [47] …”

Boron, aluminium, gallium, indium and thallium

“…283 The HOC 6 H 2 -4-Me-2,6-{P(C 6 H 4 -2-SMe) 2 } 2 ligand proved an effective soft bicompartmentalising ligand for Tl(I), its outer contacts being very distant and diffuse and very soft indeed. 284 As in most years, the optics of macrocyclically-bound Tl(I) systems were considered. 285 Distorted cubic cage motifs are seen in [TlOC 6 H 3 (CF 3 ) 2 ] 4 Á thf 286 and [Tl 4 (m 8 -SB) 2 ] n (H 2 SB = {(HO-4-C 6 H 4 ) 2 SO 2 } 2 ).…”