Study of Donor–Acceptor Bonds on the N‐Coordinated Sn/Pb(II) Atoms in peri‐Substituted Naphthalenes: Evidence of Pb→B Interaction

Abstract

Peri‐substituted naphthalene derivatives, namely, N‐coordinated plumbylenes 1‐PPh2‐8‐PbL‐C10H6 (4) and 1‐BCy2‐8‐PbL‐C10H6 (5) (L = 2,6‐(Me2NCH2)2C6H3) were prepared. Compounds 4 and 5 allowed studying interactions between the Pb atoms with the either Lewis acidic (BCy2) or Lewis basic sites (PPh2). Addition of an external Lewis acid (BH3·SMe2) to 5 provided the complex 1‐BCy2‐8‐[(BH3)2L]Pb‐C10H6 (7), in which both NMe2 groups of the ligand L were coordinated by BH3. This reaction has also been used for the synthesis of a tin analogue 1‐BCy2‐8‐[(BH3)2L]Sn‐C10H6 (6). New complexes 4–7 were also compared with the previously known, tin(II) analogues 1‐PPh2‐8‐SnL‐C10H6 (1), 1‐PPh2‐8‐[(BH3)2L]Sn‐C10H6 (2), 1‐BCy2‐8‐SnL‐C10H6 (3). This set of compounds allowed us to study influence of the P→E and E→B peri‐contacts upon the redox potentials E1/2 (ox1) by the cyclic voltammetry. As the result, the selective oxidation of E(II) atom was also studied and the new organotin(IV) sulfide [1‐PPh2‐8‐LSn(C10H6)(µ‐S)]2 (9) was prepared, the product of exclusive oxidation of the tin(II) atom in 1. Beside this, the evaluation of the P→E and E→B peri‐contacts in the neutral molecules, the first and second ionization energies (IE) were calculated. For this reason, electronic properties, full structural optimizations were conducted with density functional theory (DFT) for all possible combinations of metal atom (Sn vs. Pb), Lewis acid (N→Sn/Pb vs. N(BH3)Sn/Pb), peri‐substituents (BCy2 vs. PPh2), and for three molecular charges (0 vs. 1+ vs. 2+) on the B3PW91/6‐311+g(2df,p) level of theory.

Dismutation of Tricyanoboryllead Compounds: The Homoleptic Tetrakis(tricyanoboryl)plumbate Tetraanion

“…[16] In addition to V, a plumbylene adduct with the Lewis acid B(C 6 F 5 ) 3 [17] is a further rare example for a Pb II À B species. [18] In addition to the aforementioned Pb II/IV compounds with an electronprecise PbÀ B bond, boron clusters with Pb cluster atoms have been reported, [19] and the coordination of boratabenzenes to Pb II was described. [20] Cyanoboron compounds often exhibit high chemical, electrochemical, and thermal stabilities, [21] and cyanoborates have been tested in many materials applications.…”

“…Probably, the unprecedented stability of V is due to the sterically demanding boryl substituents [16] . In addition to V , a plumbylene adduct with the Lewis acid B(C 6 F 5 ) 3 [17] is a further rare example for a Pb II −B species [18] . In addition to the aforementioned Pb II/IV compounds with an electron‐precise Pb−B bond, boron clusters with Pb cluster atoms have been reported, [19] and the coordination of boratabenzenes to Pb II was described [20]…”

Dismutation von Tricyanoborblei‐Verbindungen: Das homoleptische Tetrakis(tricyanoboryl)plumbat‐Tetraanion

“…Die unerwartet hohe Stabilität von V ist vermutlich auf die sterisch anspruchsvollen Borylsubstituenten zurückzuführen [16] . Ein weiteres seltenes Beispiel für eine Pb II ‐B‐Spezies ist ein Plumbylen‐Addukt [17] der Lewis‐Säure B(C 6 F 5 ) 3 [18] . Neben den zuvor genannten Pb II/IV ‐Verbindungen mit einer elektronenpräzisen Pb‐B‐Bindung, sind Borcluster mit Pb Cluster ‐Atomen [19] und Koordinationsverbindungen von Boratabenzolen mit Pb II weitere Beispiele für Bor‐Blei‐Verbindungen [20]…”

“…[16] Ein weiteres seltenes Beispiel für eine Pb II -B-Spezies ist ein Plumbylen-Addukt [17] der Lewis-Säure B(C 6 F 5 ) 3 . [18] Neben den zuvor genannten Pb II/IV -Verbindungen mit einer elektronenpräzisen Pb-B-Bindung, sind Borcluster mit Pb Cluster -Atomen [19] und Koordinationsverbindungen von Boratabenzolen mit Pb II weitere Beispiele für Bor-Blei-Verbindungen. [20] Cyanoborverbindungen weisen häufig hohe chemische, elektrochemische und thermische Stabilitäten auf.…”

Bisstibane–distibane conversionviaconsecutive single-electron oxidation and reduction reaction

“…2 FLPs are mainly based on N/B, P/B, P/Al combinations, but related systems have also been reported, 3 including P-coordinated tetrylenes 4 and peri -substituted naphthalene complexes with P→E and EB (E = Sn, Pb) interactions. 5 In contrast, comparable complexes containing heavy pnictogen atoms are rare.…”