Oxidative Addition of Diphenyldichalcogenides PhEEPh (E = S, Se, Te) to Low-Valent CN- and NCN-Chelated Organoantimony and Organobismuth Compounds

Abstract

The reactions of the organoantimony(I) compound L1 4Sb4 (1) (where L1 = [o-C6H4(CHNC6H3(i-Pr)2-2,6)]) with diphenyldichalcogenides PhEEPh (E = S, Se, or Te) gave compounds L1Sb(EPh)2 (E = S (2), Se (3), Te (4)) as the result of the oxidative addition of the antimony(I) atom across the chalcogen–chalcogen bond. The reaction of diphenyldichalcogenides PhEEPh with an in situ prepared organobismuth(I) compound (via reaction of the parent chloride L1BiCl2 (5) with two equivalents of K[B(s-Bu)3H]) gave surprisingly diorganobismuth compounds L1 2Bi(EPh) (E = S (6), Se (7), Te (8)) as the major products along with only a trace amount of the intended compounds L1Bi(EPh)2 (E = S (9), Se (10), Te (11)). It turned out that this is the result of instability of 9–11 in solution, and their decomposition provided compounds 6–8. The bismuth compounds containing the pincer-type ligand L2 (L2 = [o,o-C6H3(CH2NMe2)2]) containing an extra donor pendant arm were studied with the aim to support their stability by an additional N→Bi interaction. Thus, in situ preparation of the organobismuth(I) compound from L2BiCl2 (12) and two equivalents of K[B(s-Bu)3H] followed by the addition of PhEEPh gave compounds L2Bi(EPh)2 (E = S (13), Se (14), Te (15)). Compounds 13–15 showed no tendency for redistribution reaction, contrary to 9–11, due to the rigid coordination of both nitrogen donor atoms of the ligand L2 to the bismuth atom. All studied compounds were characterized by the help of 1H and 13C NMR spectroscopy, by elemental analysis, and except compounds 4, 14, and 15 by single-crystal X-ray diffraction analyses.

Covalently bonded compounds of heavy group 15/16 elements – Synthesis, structure and potential application in material sciences

“…[81,46] M a n u s c r i p t Unfortunately, the crystal quality of Bi(SeTrip) 3 was too low to allow a detailed structure discussion. Bi(SePh) 3 crystallizes with two independent molecules in the asymmetric unit and forms a trigonal-pyramidal structure as was observed for Sb(SeMe) 3 [57] Ph 2 BiSePh (2.704(3) Å), [22] and Bi(SeR) 3 (R = 2-(4,4-dimethyloxazolino)phenyl, 2.6910(8), 2.7049(9), 2.7454(9) Å). [58] Moreover, the terminal Bi-Se bond lengths as-observed in the polynuclear bismuthselenolates, [Bi 4 (μ-SePh) 5 (SePh) 8 ] − (2.646(4)-2.737(4) Å) and [Bi 6 (μ-SePh) 6 (SePh) 10 Br 2 ]…”

“…[59] The Sb-Te bond length of Et 2 SbTeEt is comparable to the telluradistibirane Bbt 2 Sb 2 Te (Sb-Te 2.7607(7), 2.7719(6) Å) [62] and the Bi-Te bond length in respectively. [57] In contrast, the Bi-Te bond length of Et 2 BiTeEt is slightly shorter than the shortest Bi-Te distance observed in the crystal of Bi 2 Te 3 (3.066(2) Å). [65] The slightly bigger sum of the bond angles at the Sb atom of Et 2 SbTeEt (286.0(3)°) compared to the Bi atom in Et 2 BiTeEt (282.3(8)°) points to a slightly higher p-character of the bonding electron pairs in Et 2 BiTeEt compared to Et 2 SbTeEt.…”

“…[57] These compounds were found to decompose in solution with elimination of Bi(EPh) 3 [22] and Bi(SeR) 3 (R = 2-(4,4-dimethyloxazolino)phenyl, 2.6910(8), 2.7049(9), 2.7454(9) Å ), [58] the only structurally characterized compounds containing a Bi-Se single bond, as well as with the sum of the covalent radii ∑ cov (Bi,E) = 2.67 (E = Se), and 2.87 Å (E = Te) as reported by…”

“…Solid state structure of R 2 BiTePh (R = o-C 6 H 4 (CH=NC 6 H 3 -2,6-i-Pr 2 ). [57] The M-Te bond length in Et 2 SbTeEt (2.7834(4) Å)) and Et 2 BiTeEt (2.9116(5) Å) (Figs. 2,…”

“…[64] In addition to the compounds mentioned before, several intermolecular stabilized compounds of the type RM(ER') 2 have been synthesized, [77,78] often by reactions of donor-stabilized lowvalent organoantimony and -bismuth compounds of the type MR (M = Sb, Bi), in which the metal centers adopt the formal oxidation state +I, with diaryldichalcogenanes E' 2 Ar 2 (E' = S, Se, Te). [57,79] While the majority of these compounds adopt monomeric structures in the solid state, most likely a result of the steric demand of the bulky organic substituent as well as the intramolecular stabilization by the pendant donor group, some compounds were found to form intermolecular contacts, resulting in the formation of weakly bonded dimers in the solid state. ).…”