Lewis-Base Adducts of Lead(II) Compounds. XII. Synthetic, Spectroscopic and Structural Studies of Some 1:1 Adducts of Lead(II) (Pseudo-)Halides With Aromatic Bidentate Ligands

Abstract

Syntheses and room-temperature single-crystal X-ray structure determinations are recorded for some 1 : 1 adducts of lead(II) (pseudo-)halides with 1,10-phenanthroline (' phen ') and 2,2'-bipyridine (' bpy '). [( phen )PbX2](∞|∞), X = Cl , Br, I, have been refined in a common monoclinic C2/c setting, a ≈ 16.2, b ≈ 10.6, c ≈ 8.25 Ǻ, β 105°, Z = 4 f.u .; (conventional R on |F| 0.034, 0.046, 0.043 for No = 1694, 1626, 1387 independent, 'observed' (I > 3σ(I)) reflections respectively); [( bpy )PbI2](∞|∞) is isomorphous with similar cell dimensions (R 0.035 for No 1263), but, in its chloride counterpart, the symmetry is degraded to P21/c, a 15.336(5), b 9.476(5), c 8.191(3) Ǻ, β 92.81(3)�, Z = 4 (R 0.041 for No 2849). In the C2/c model the lead atoms are disposed on crystallographic 2 axes, as also are the associated N,N′- bidentate ligands, with the six-coordinate (cis-N2) Pb (μ-X)4 environments linked in an infinite …(μ-X)2Pb(μ-X)2Pb… one-dimensional polymeric chain by bridging halogen atoms. A somewhat similar, albeit more complex, array is found in [( bpy ) Pb (SCN)2](∞|∞), monoclinic, C2/c, a 17.655(6), b 12.027(3), c 6.794(1) Ǻ, β 107.03(2)°, Z = 4 (R 0.028 for No 1064), isomorphous with its previously studied phen analogue, in which a web of bridging SCN units is found. Stacks of successive strands up b have interleaving arrays of ligands and (pseudo-)halide atoms. The far-infrared spectrum of [( phen )PbCl2] shows four strong, broad bands at 152, 144, 116 and 96 cm-1 which are assigned as vPb-Cl. The corresponding bands in the bromo and iodo complexes are shifted to below 100 cm-1, revealing sharper bands at about 120 and 150 cm-1 which are assigned to vPb -N modes. The low wavenumbers of the vPb-X bands are indicative of weak Pb-X bonding. The far-infrared spectrum of the previously reported [( phen ) Pb (NCS)2] complex is similar to that of the chloro complex, consistent with its similarity in structure.

Thermally stable lead(ii) amidinates and guanidinates

“…[PbCl 2 (L)] n (L = phen, bpy; Pb-Cl 2.858(3), 3.023(3) A ˚, in which far infrared data suggested only weak Pb-Cl binding. 12 For 2 and 3, the N-Pb(1)-Cl (1) angles are all approximately equal as was observed for monomeric [Pb(nacnac)Cl] (although the current values are larger due to the smaller bite angle of the amidinate NCN backbone), suggesting that the molecular association is sufficiently weak as to not perturb the lead coordination environment. However, for 4, which has a PbÁ Á ÁCl distance only marginally shorter than for 3, there is one acute and one obtuse N-Pb(1)-Cl(1) angle, which, along A small sample of yellow crystals of [Pb(CyG)Cl], covered in a viscous fluorocarbon oil (used to mount crystals for X-ray analysis) was exposed to air.…”

Crystallographic report: Crystal structure of bis[dipyrido[3,2,‐a:2′,3′‐c]phenazine]lead(II)diiodide

“…4,5 The N(1)-Pb-N(2) bite angle in I is only 62.57 (12) • , whereas the bite angles in Programs used: teXsan, SHELXL and ORTEP. CCDC deposition number: 195974.…”

1,10-Phenanthroline as an Efficient Bifunctional Passivating Agent for MAPbI3 Perovskite Solar Cells

“…After complexation of PbI 2 with 1,10-phen, the typical Raman bands of PbI 2 (71, 95, and 111 cm –1 ), shown in Figure a, and the Raman signals of the 1,10-phen powder (for example, the peaks at 411, 711, 1035, 1295, and 1404 cm –1 ), shown in Figure b, are retained with a uniform upshift. Furthermore, new Raman bands are observed for the complex at 249 and 265 cm –1 wavenumbers, shown in Figure a with an asterisk, which is attributed to the Pb–N­(1,10-phen) stretching vibrations. − Indeed, these upshifted and observed new signals in Raman spectrum for the complex powder are both good indicators of chemical interactions between the small molecule ligand and Pb atoms and support the anchoring ability of the 1,10-phen on the unreacted PbI 2 and undercoordinated lead ions of the perovskite surface.…”