Multinuclear Alkali Metal Complexes of a Triphenylene-Based Hexamine and the Transmetalation to Tris(N-heterocyclic tetrylenes) (Ge, Sn, Pb)

Abstract

A C3-symmetric hexamine (LH6) based on the triphenylene and ortho-phenylenediamine (PDAH2) skeletons has been synthesized, and was partially or fully deprotonated upon treatment with alkali metal agents to afford amino-amido or diamido coordination sites. Four alkali metal complexes, the dinuclear [Na2(LH4)(DME)5] (1) and [K2(LH4)(DME)4] (2), trinuclear [K3(LH3)(DME)6] (3), and hexanuclear [Li6(L)(DME)6] (4), were obtained and used in transmetalation/ligand exchange with other metals. The hexalithium salt of the fully deprotonated ligand, [Li6L], reacted with heavier group 14 element halides to yield three tris(N-heterocyclic tetrylenes), the germylene [Ge3(L)] (5), stannylene [Sn3(L)] (6), and plumbylene [Pb3(L)] (7). The synthesis and crystal and electronic structures of these compounds are reported.

Effect of the Lead(II) Bond Angle on the Reactivity of Diaminoplumbylenes toward Ammonia: From Inertness to Immediate Ammonolysis

“…The Pb atoms show weak Pb···C aryl contacts of 3.63 and 3.69 Å (not shown in Figure ), which is ca. 0.7 Å below the sum of the van der Waals radii of C and Pb (4.37 Å), as is not uncommon for diaminoplumbylenes with bulky N -aryl substituents . The only closely related Pb II compound known to date appears to be [Pb­(μ-NH 2 ) 2 Ar*] 2 (vide supra) …”

N,N′-Dipp-o-phenylene-diamido Dianion: A Versatile Ligand for Main Group Metal–Metal-Bonded Compounds

“…Stable heavier analogues of alkane (R 3 E–ER 3 ), alkene (R 2 EER 2 ), alkyne (REER), and carbene (R 2 E:) of group 14 elements/metals (E = Si, Ge, Sn, and Pb; R = alkyl/aryl groups and/or other ligands) have been extensively studied in the past decades (some selected examples are listed in Table S1), most of which display the characteristic trans -bent conformation. Especially, in the case of germanium, the compounds can roughly be divided into five classes (Chart ): digermane A , digermene B , germylene C , digermyne D , and digermylene E , in which the formal oxidation state of Ge is +3, +2, +2, +1, +1, respectively.…”

“…It is also much longer than that in the germanium­(I) dimers with N , N ′-chelating ligands, amidinate, and guanidinate, [{Ge­(Piso)} 2 ] (Piso = [(ArN) 2 CBu t ] − , 2.6380(8) Å) and [{Ge­(Giso)} 2 ] (Giso = [(ArN) 2 CNPr i 2 ] − , 2.6721(13) Å; Ar = dipp) . Notably, although digermylene (Ge­(I)) compounds have been obtained with various ligands and the monomeric germylenes (Ge­(II)) of α-diimine and ortho -phenylenediamine ligands are known, , digermylenes with these two types of ligands have not been reported. It is recognized that dimeric germanium compounds can display bond orders between 1 and 3 (Chart ), as have been studied by both experimental and theoretical methods.…”

Revealing Germylene Compounds to Attain Superbasicity with Sigma Donor Substituents: A Density Functional Theory Study

“…The divalent germanium compounds (germylene(II), GeR 2 )a nd its carbene analogues have received much attention overt he last four decades. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] However, N-heterocyclicg ermylenes (NHGe)a re less exploredt han their lower N-heterocyclicc arbene analogues (NHCs are cyclic carbenec ompounds with two neighboring nitrogen atoms). [17] In 1991 Ardengo first reported the isolation of free NHCs using adamantyl units to avoid dimer formation.…”

“…The divalent germanium compounds (germylene(II), GeR 2 ) and its carbene analogues have received much attention over the last four decades . However, N ‐heterocyclic germylenes (NHGe) are less explored than their lower N ‐heterocyclic carbene analogues (NHCs are cyclic carbene compounds with two neighboring nitrogen atoms) .…”