Dichotomy between Palladium(II)–Tin(II) and Palladium(0)–Tin(IV) in Complexes of a Sn,As‐Based Chelate Ligand

Abstract

A dinuclear Pd–Sn bonded complex is reported, in which the interaction of the formally tin(II)‐based ligand, [2‐MeBrSnC6F4AsPh2]–, with palladium appears to be best described as PdI–SnIII or Pd0–SnIV.

Synthesis and Oxidation of a Paddlewheel‐Shaped Rhodium/Antimony Complex Featuring Pyridine‐2‐Thiolate Ligands

“…[18e] Thus, the S2ÀRh1ÀSb1ÀN2 torsiona ngle (408)i s noticeably wider than the corresponding dihedral angles of the other three pyS ligands, and the Sb1-N2d istance (involving the Natom of the RhÀSÀRh bridging pyS ligand) is the longest in the range of 2.27 to 2.68 .T he average Sb-N distance in 1 (2.43 )i sc omparable to those found for Sb III complexes with electronegative substituents and coordinated pyridine (e.g.,S bCl 2 N 3 (py) 2 : [19] 2.43 ;[ (py)Sb(1,2-O 2 C 6 H 4 )O] 2 : [20] 2.49 ). Furthermore, the average CÀS( 1.738(2) vs. 1.736(3) )a nd CÀNb ond lengths (1.348(3) vs. 1.346(8) )o ft he bridging pyS ligands did not change significantly upon oxidizing 1 to 2.A lso, in both complexes, the two CÀNb ond lengths within each pyS moietya re very similar to each other (N 1 ÀC 2 1.347(3) vs. N 1 ÀC 6 1.349(3) in 1,N 1 ÀC 2 1.338 (8) vs. N 1 ÀC 6 1.354 (8) in 2). 2.36 )a re significantly shorter than the Rh-S contacts trans to Sb (2.53 )a nd are comparable to those found in Rh(pyS) 3 (avg.…”

“…[4] For heterobimetallic Pd/Sn systems featuring mt [5] or pyS [6] ligands, the charged elocalization within the bridging ligands leads to more ambiguous assignment of bondings ituations between the metal atoms, that is, it raises the question of whether the Group 14 elements (E 14 ) should be referred to as s-acceptor (TM!E 14 , III Z )o rs-donor (TM ! E 14 , III L ), or the intermediate case with ac ovalent metalmetal bond (TMÀE 14 , III X ,S cheme 1; this feature was also reportedf or related complexes bearing 2-pyridyldiphenylphosphine [7] or ortho-metallated arsines [8] as bridgingligands).…”

“…2.28 )a re shorter compared to the RhÀSa nd SbÀNb onds in 1.T his is an indication that the oxidation of 1 to form 2 affects not only the electronic features of the Sb atom but rathert he electronic distribution of the heterobimetallic Rh-Sb core. Furthermore, the average CÀS( 1.738(2) vs. 1.736(3) )a nd CÀNb ond lengths (1.348(3) vs. 1.346(8) )o ft he bridging pyS ligands did not change significantly upon oxidizing 1 to 2.A lso, in both complexes, the two CÀNb ond lengths within each pyS moietya re very similar to each other (N 1 ÀC 2 1.347(3) vs. N 1 ÀC 6 1.349(3) in 1,N 1 ÀC 2 1.338 (8) vs. N 1 ÀC 6 1.354 (8) in 2). Thus, there are no structural hints at differences between 1 and 2 in p-delocalization within the bridging anionic ligands.…”

“…The true character of the MÀM' bond in such ac ompound, and changes in the bonding mode upon substitution or redox reactions, cannot be accounted for in this formalism. E 14 , III L ), or the intermediate case with ac ovalent metalmetal bond (TMÀE 14 , III X ,S cheme 1; this feature was also reportedf or related complexes bearing 2-pyridyldiphenylphosphine [7] or ortho-metallated arsines [8] as bridgingligands). Whereas crystallographic analyses merely hint at the presence or absenceo fabond (according to interatomic separations observed), Mçssbauer spectroscopy (for suitable nucleis uch as 121 Sb) and computational analyses allow for deeper insights into the nature of the electronic situation of the metal atoms andt he intermetallic bond.…”

Rational Syntheses and Serendipity: Complexes [LSnPtCl2(SMe2)]2, [{LSnPtCl(SMe2)}2SnCl2], [(LSn)3(PtCl2)(PtClSnCl){LSn(Cl)OH}], and [O(SnCl)2(SnL)2] with L=MeN(CH2CMe2O)2

“…This is in accordance with the valuesc alculated for comparable PtSn 2containing compounds. [44] In order to get deeper insight into this exciting electronic situation we performed a charge-decomposition analysis. Together with the charge for Pt of + 0.12, this is indicative for the Sn IV !…”