Facile Synthesis of Bismuth(III) and Antimony(III) Complexes Supported by Silylated Calix[5]arenes.

Abstract

A series of bismuth(III) and antimony(III) complexes supported by silicon-containing calix[5]arene ligands were synthesized and fully characterized by NMR, X-ray, IR, mp, UV/vis, and elemental analysis. Reaction of the para-tert-butylcalix[5]arene [(t)BuC5(H)(5)] disodium salt, Na(2) x (t)BuC5(H)(3), with 1 equiv of R(2)SiCl(2) (R = Me, (i)Pr, Ph, CH=CH(2)) or treatment of the (t)BuC5(H)(5) lower rim monobenzyl ether [(t)BuC5(Bn)(H)(4)] in a 1:1 ratio with Me(2)Si(NMe(2))(2) yields the (t)BuC5(SiRR')(H)(3) (1-5) and (t)BuC5(Bn)(SiMe(2))(H)(2) (6) ligands, respectively. The (1)H NMR spectra of the (t)BuC5(SiRR')(H)(3) (1-5) ligands show three pairs of doublets and three singlets for the (t)Bu peaks, consistent with a C(s) symmetry. In the case of the (t)BuC5(Bn)(SiMe(2))(H)(2) (6) ligand, the presence of the monobenzyl group changes the (1)H NMR patterns to indicate a C(1) symmetry. Treatment of (t)BuC5(SiRR')(H)(3) (1-5) or (t)BuC5(Bn)(SiMe(2))(H)(2) (6) with 1 equiv of M(O(t)Bu)(3) (M = Bi, Sb) or Sb(NMe(2))(2) readily yields metalated products of the type [M{(t)BuC5(SiRR')}] (7-16) and [MX{(t)BuC5(Bn)(SiMe(2))}] (X = O(t)Bu, (NMe(2))(2)) (17-19), respectively. All monometallic complexes [M{(t)BuC5(SiRR')}] (7-19) display excellent solubility in organic solvents including pentane and hexane. The (1)H NMR patterns for complexes 7-16 are consistent with a 1,2- or 1,3-alternate conformation while complexes [MX{(t)BuC5(Bn)(SiMe(2))}] (17-19) display patterns for a C(1) symmetry. All crystals show monomeric structures. Ligand (t)BuC5(SiPh(2))(H)(3) (3) displays a distorted cone conformation while the presence of the monobenzyl ether in (t)BuC5(Bn)(SiMe(2))(H)(2) (6) forces a partial cone conformation. Complexes 7-19 all display a distorted 1,2-alternate conformation with the metal centers displaying coordination numbers of three, four or five. No Si...M interactions were observed.

A Redox‐Confused Bismuth(I/III) Triamide with a T‐Shaped Planar Ground State

“…[15a] Collectively,t hese features suggest that 2 is aB i I compound in the solid, solution, and gas phases,made accessible in the absence of external reductants by partial oxidation of the tridentate ligand as per Scheme 1b.I ti si nteresting therefore that as urvey of its reactivity revealed behavior Reaction of 2 with pentafluorophenol showed complete loss of the blue color and conversion into N 3 H 3 and the known compound Bi(OC 6 F 5 ) 3 [20] at all stoichiometries,i ndicating ametathesis reaction that is well-known for Bi III triamides. [21] Similarly,the mixture of 2 and PCl 3 gave 3 under elimination of BiCl 3 (Scheme 3). Although the reaction is quantitative by 31 PNMR spectroscopy (see Figure S16), the yield upon isolation is low (35 %).…”

“…Reaction of 2 with pentafluorophenol showed complete loss of the blue color and conversion into N 3 H 3 and the known compound Bi(OC 6 F 5 ) 3 [20] at all stoichiometries,i ndicating ametathesis reaction that is well-known for Bi III triamides. [21] Similarly,the mixture of 2 and PCl 3 gave 3 under elimination of BiCl 3 (Scheme 3). Although the reaction is quantitative by 31 PNMR spectroscopy (see Figure S16), the yield upon isolation is low (35 %).…”

Bismuth(iii) complexes derived from α-amino acids: the impact of hydrolysis and oxido-cluster formation on their activity against Helicobacter pylori

“…In addition to having been effective in the formation of bismuth(III) amino-arenesulfonates, it has also been used successfully for the synthesis of a variety of bismuth(III) compounds such as silanolates, 37-40 aminetris( phenoxides), 41 calixarenes, [42][43][44] allyloxides, 45 and sulfabenzimides. Unlike BiPh 3 , however, it is air and moisture sensitive and is not so easily handled.…”

“…Unlike BiPh 3 , however, it is air and moisture sensitive and is not so easily handled. In addition to having been effective in the formation of bismuth(III) amino-arenesulfonates, it has also been used successfully for the synthesis of a variety of bismuth(III) compounds such as silanolates, [37][38][39][40] aminetris( phenoxides), 41 calixarenes, [42][43][44] allyloxides, 45 and sulfabenzimides. 46 Initial experiments involved treatment of the target α-amino acid with freshly prepared [Bi(O t Bu) 3 ] 37 in dry THF, at room temperature, and under a nitrogen atmosphere.…”

Bismuth⋅⋅⋅π arene interaction in [Bi{OC6H4(CH2C6H5)-2}3]2

“…ii) R = iPr; R' = Cl, Br, OMe] and some bismuth calixarene complexes were reported as well, but Bi⋅⋅⋅π arene interactions are not discussed for these compounds (Brym et al, 2006;Hanna et al, 2002;Kaur and Singh, 2012;Kou et al, 2009;Mendoza-Espinosa and Hanna, 2009a;Mendoza-Espinosa and Hanna, 2009b;Mendoza-Espinosa and Hanna, 2009c;Mendoza-Espinosa et al 2009;Sauer et al, 1990;Whitmire et al, 2000).…”