Chemistry of subvalent main group metals with dithiolates. Part 2. X-Ray structural, thermal, and theoretical investigations on the novel one-dimensional stacking structure K₂[Pb{S₂CC(CN)₂}₂]·2H₂O

A Short Pb···Pb Separation in the Polymeric Compound Bis(pyrrolidinecarbodithioato)lead(II) and a Conformational Pathway Interconversion for the “PbIIS4” Framework

“…From a literature search using the Cambridge Structural Database, 19 we formulated Table 4 which summarizes pertinent geometrical information of Pb II (XS 2 ) 2 compounds where the ligand is a bidentate anionic species. The structure of the title compound resembles most that of Hummel-1 20 (see Table 4), where the pyramid is described by equal trans angles: 113.3(3)°a nd 113.6(3)°, respectively, and with the separations S1-S2 ) S3-S4 ) 2.97(2) Å and S1-S4 ) S2-S3 ) 3.79(2) Å. Other similarities between this species and the title compound exist as well and are the Pb-S primary bonds (2.88(1) Å) and the bite angle of the chelating ligands 62.0(3)°.…”

Reexamination of Lead(II) Coordination Preferences in Sulfur-Rich Sites: Implications for a Critical Mechanism of Lead Poisoning

“…The observation that Pb assumes a preferred coordination mode of Pb−S 3 even when an additional thiolate is available for binding appeared to contradict several reports in the literature stating that Pb(II) assumes a tetrahedral Pb−S 4 coordination mode in thiol-rich small molecules. ,,, Experimental reexamination of one of the classic “Pb−S 4 ” compounds, 2 , using X-ray absorption spectroscopy and X-ray crystallography revealed that the original structure had been misinterpreted: the compound actually exists as a [Pb( i -mnt) 2 ] 2 4- dimer in the solid state, with each Pb(II) assuming a distorted six-coordinate geometry.…”

“…These supramolecular interactions result in increased coordination numbers for lead, generally 5, 6, or 8. A number of researchers have recognized the existence of these secondary Pb−S interactions; ,− such interactions also appear in several other crystallographically characterized compounds but were not noted. ,,, The one truly four-coordinate compound in the database is lead(II) bis{2,6-bis[bis(trimethylsilyl)methyl]-4-[tris(trimethylsilyl)methyl]phenyl trithiocarbonate} . The Pb(II) in this complex is forced into four-coordination by the extreme bulk of the ligands; the lead is so buried within the ligands that it cannot form an extended structure.…”

“…Here, we report detailed structural studies on the coordination geometry of four Pb(II)-peptide complexes and two Pb(II) coordination compounds. We have used X-ray absorption spectroscopy (XAS) to characterize the lead-bound forms of a series of structural zinc-binding peptides as well as the tris(2-mercapto-1-phenylimidazolyl)hydroborato lead complex [(Tm Ph )Pb][ClO 4 ] ( 1 ) and tetraphenylarsonium Pb(II) iso -maleonitriledithiolate, [AsPh 4 ] 4 [Pb 2 ( i -mnt) 4 ] ( 2 ). ,, In addition, we report the low-temperature UV−visible absorption spectra of the series of Pb−peptide complexes and the affinity of Pb(II) binding to these domains. These studies reveal significant differences between the Pb(II) coordination geometry and that of Zn(II) in the same peptides, and we propose that the difference in coordination preference and geometry is a concrete way that lead binding disrupts the structure and function of these domains and thus contributes to the developmental problems associated with lead poisoning.…”

Lead Coordination and Organometallic Compounds: Classification and Analysis of Crystallographic and Structural Data

“…By far the most common ligands to yield a four coordinate environment about Pb(ll) are bidentate S-donor ligands [36][37][38][39][40][41][42][43][44][45][46][47], An unsymmetrical (anisobidentate) coordination of the chelating ligands is observed with unequal Pb-S distances, except for one example [45] where all four Pb-S distances are 288(1) pm. The others have two sets of distances with mean values of 275 and 292 pm.…”