Synthesis and Characterization of Bromo- and Bromochloroplumbates(II). Crystal Structures of [Ph₄E]₂[Pb₃Br₈] (E = P, As) and [Ph₄P][PbBrCl₂] • CH₃CN

Abstract

Tetraphenylphosphonium(arsonium) Octabromotriplumbate, Tetraphenylphosphonium Bromodichloroplumbate, Quantum Chemical Calculations [PhiPMPb^Brg] and [PhuAshtPb^Brg] crystallize both in the monoclinic space group Po2\ln. The lattice parameters of [PluPMPb^Brg] are a = 14.637(7), b = 8.151(3), c = 23.388(8) Ä, ß = 106.02(3)°, Z = 2 and of [PluAsMPbsBrg] are a = 14.697(7), b = 8.219(3), c = 23.527(8) A, ß = 106.27(3)°, Z = 2. The lattice parameters of [PhuPHPbBrClilCH^CN, which crystallizes in the triclinic space group (P I), are a = 9.435(3), b = 10.2577(14), c = 14.055(2) Ä, a = 88.320(11)°, ß = 84.82(2)°, 7 = 84.19(2)°, Z = 2. 207Pb NMR shifts of halogenoplumbates in solution are reported.

s–p Mixing in Stereochemically Active Lone Pairs Drives the Formation of 1D Chains of Lead Bromide Square Pyramids

“…Mn­(DMF) 6 Pb 2 Br 6 is isostructural to a previously reported material where Sn and I are found in place of Pb and Br, as well as to another material where Mg and I are found in place of Mn and Br . The geometry of the Pb–Br chains is similar to what is seen in a few other compounds where the counterion is tetraphenylphosphonium or tetrabutylphosphonium, the metal Pb, and the halide Cl, I, , or a disordered mix of Br and Cl . On the basis of our examination of the Cambridge Structural Database, we believe Mn­(DMF) 6 Pb 2 Br 6 is the first structurally characterized compound to contain edge-sharing chains of Pb–Br square pyramids, suggesting that all halides are compatible with this motif.…”

“…In contrast, the Pb–Br bond to the axial Br is much shorter (2.71 Å), which we hypothesize is shorter because this Br atom is unshared. A shorter bond to unshared halides is also observed in other pyramidal − and octahedral lead and tin halide compounds.…”

Hybrid Inorganic–Organic Complexes of Zn, Cd, and Pb with a Cationic Phenanthro-diimine Ligand

“…In contrast to ionic compounds 1 and 2 , lead­(II) bromide produced overall neutral molecular entity 3 , which can be seen as a zwitterionic complex built of two cationic ligands coordinated to an anionic bromoplumbate cluster featuring a discrete [Pb 3 Br 8 ] 2– core (Figure ); the complex conceptually resembles the [Cu 4 I 6 ] 2+ clusters stabilized by [RP­(pyridine) 3 ] + ligands . The anions of the same composition but of somewhat different geometry were found as 1D polymers in salts [PR 4 ] 2 [Pb 3 Br 8 ]. , The trimetallic motif contains a central seesaw [PbBr 4 ] 2– fragment, which is linked to the lateral PbBr 2 units via bromide bridges. The geometry of tetracoordinate [PbBr 4 ] 2– is known for n s 2 metal halides , and is derived from a trigonal bipyramid with a 6s 2 electron pair of Pb­(II) being in the equatorial plane. , The bond distances from the bridging halides Br(3) and Br(4) to the pendant Pb(1) atom (Br­(3/4)–Pb(1) = 3.0893(4) and 3.2068(8) Å) are visibly longer than those within the [PbBr 4 ] 2– block (Br­(3/4)–Pb(2) = 2.9932(4) and 2.7250(5) Å).…”

Tetraorganopnictonium and Alkali Metal Salts of Pyridine‐2,6‐di‐tetrazolate

“…10 Å 3 per cation. For the pair of compounds ( E Ph 4 ) 2 [Pb 3 Br 8 ] ( E = P or As) in P 2 1 / n (Z = 2) a value of 52/4 = 13 Å 3 per cation is calculated and the corresponding difference for (EPh 4 )[Fe 2 Cl 6 ] ( P 1, Z = 2) calculates to 21/2 = 10.5 Å 3 per cation. Although the volume difference Δ[ V (AsPh 4 + ) – V (PPh 4 + )] ≈ 22 Å per cation resulting from our Rietveld fits is somewhat larger than the values found in the literature, it is at least in the same range and goes in the expected direction.…”