Synthesis, X-ray structures and reactivity of calix[5]arene bismuth(iii) and antimony(iii) complexes

Abstract

A series of calix[5]arene bismuth(III) and antimony(III) mono- and bimetallic complexes were synthesized and fully characterized by NMR, X-ray, IR, mp, UV-Vis and elemental analysis. Reaction of p-tert-butylcalix[5]arene (tBuC5(H)5) trianionic salts M'3.tBuC5(H)2 (M'=Li, Na, K) with MCl3 (M=Bi, Sb) yielded monometallic complexes [Bi{tBuC5(H)2}] 1 and [Sb{tBuC5(H)2}] 2, respectively. 1H NMR spectra of both complexes showed two remaining OH groups available for further reactivity. Alternatively, complexes 1 and 2 can be obtained by reacting tBuC5(H)5 in a 1:1 ratio with M(OtBu)3, but the yields are lower. When the tBuC5(H)5 lower rim monobenzyl ether [tBuC5(Bn)(H)4] is treated in a 1:1 ratio with Bi(OtBu)3, the monometallic complex [Bi{tBuC5(Bn)(H)}]2 3 is prepared. If, however, [tBuC5(Bn)(H)4] reacts with Sb(NMe2)3 or Sb(OtBu)3 in a 1:2 ratio the production of the bimetallic complex [Sb2O{tBuC5(Bn)}] 4 is observed. p-Benzylcalix[5]arene (BnC5(H)5) reacts with excess Bi(OtBu)3 to produce the bimetallic complex [Bi2O{BnC5(H)}]2 5. 1H NMR spectra of 5 display patterns characteristic for a cone conformer in solution. Treatment of calix[5]arene [HC5(H)5] with one equivalent of Bi[N(SiMe3)2]3 or with 0.75 equivalents of Sb(NMe2)3 yields bimetallic complexes [Bi2O{HC5(H)}] 6 and [Sb2O{HC5(H)}] 7, respectively. The reactivity of monometallic complexes 1 and 2 was tested in order to investigate the availability of their remaining OH groups. Treatment of 1 with Bi(OtBu)3 at ambient temperature yields bimetallic complex [Bi2O{tBuC5(H)}]2 8 while the reaction of complex 2 with Sb(OtBu)3 in a 1:1 ratio produces complex [Sb2O{tBuC5(H)}] 9. The crystal structures of the monometallic bismuth complexes 1 and 3 display dimeric units with the calixarene ligands in distorted cone and "paco-in" conformations, respectively. Complexes 4, 7 and 9 are all monomeric units, displaying [(RO)2Sb]2(micro-O) cores and the calixarene ligands in 1,2-alternate conformation. The dimeric units of bimetallic complexes 5 and 8 contain Bi4O2(OR)8 core structures that force the calixarene ligands to adopt a flattened cone conformation.

Anionic Bismuth Oxido Clusters with Pendant Silver Cations: Synthesis and Structures of {[Bi4(µ3‐O)2(TFA)9Ag(tol)2]2} and {Bi4(µ3‐O)2(TFA)10(AgPPh3)2}n

“…For these bismuth atoms, there are three η 1 ‐carboxylate and one η 2 ‐carboxylate ligands occupying the five pentagonal sites. Other heterometallic Bi 4 (µ 3 ‐O) 2 compounds such as Na[Bi 4 (µ 3 ‐O) 2 (OC 6 F 5 ) 9 (C 4 H 8 O) 2 ] and Li 2 [Bi 4 (µ 3 ‐O) 2 { O ‐2‐(CH 2 CH=CH 2 )C 6 H 4 } 10 ] exhibit distortion of the core due to the effects of the presence of non‐bismuth metal ions that bind to the oxido ligands, which causes distortion from planarity , , . A comparison of the Bi hinge –O and Bi wingtip –O distances in similar compounds is given in Table .…”

“…Other heterometal- [35] exhibit distortion of the core due to the effects of the presence of non-bismuth metal ions that bind to the oxido ligands, which causes distortion from planarity. [33,40,41] A comparison of the Bi hinge -O and Bi wingtip -O distances in similar compounds is given in Table 3. In all of these compounds, the Bi-O oxide distances are considerably shorter (ca.…”

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).…”

Impact of the Exchange of the Coordinating Solvent Shell in [Bi38O45(OMc)24(dmso)9] by Alcohols: Crystal Structure, Gas Phase Stability, and Thermoanalysis

“…In the last years, polynuclear bismuth oxido clusters gained increasing interest since the clusters such as [Bi 9 O 7 (Hsal) 13 (Me 2 CO) 5 ], [Bi 38 O 44 (Hsal) 26 (H 2 O) 4 (dmf) 18 ], and [Bi 38 O 45 (Hsal) 26 (Me 2 CO) 16 (H 2 O) 2 ] were obtained starting from Bi(Hsal) 3 (H 2 sal = salicylic acid). [1] These polynuclear bismuth oxido clusters are supposed to be model compounds of the ill-defined bismuth subsalicylate, a component of Pepto-Bismol®, which is a commercial drug used worldwide in treating gastrointestinal diseases such as diarrhea and dyspepsia caused by Helicobacter pylori infections.…”

“…These polynuclear bismuth oxido clusters are supposed to be model compounds of the ill‐defined bismuth subsalicylate, a component of Pepto‐Bismol®, which is a commercial drug used worldwide in treating gastrointestinal diseases such as diarrhea and dyspepsia caused by Helicobacter pylori infections . To date, numerous bismuth oxido clusters with varying core nuclearities and ligands have been reported such as [Bi 4 (μ 3 ‐O) 2 (HO‐2‐C 6 H 4 CO 2 ) 8 ] · 2Solv (Solv = MeCN or MeNO 2 ), [Bi 2 O{BnC5(H)}] 2 and [Bi 2 O{ t BuC5(H)}] 2 [BnC5(H) 5 = para ‐benzylcalix[5]arene; t BuC5(H) 5 = para ‐ tert ‐butylcalix[5]arene], [Bi 4 O 2 {HC8}] and [Bi 4 O 2 {BnC8}] [HC8(H) 8 = calyx[8]arene; BnC8(H) 8 = para ‐benzylcalix[8]arene], [Bi 6 (μ 3 ‐O) 7 (μ 3 ‐OC 6 F 5 )][Bi(OC 6 F 5 ) 4 ](thf) 2 , [Bi 6 O 5 (OH) 3 (NO 3 ) 5 ] · 3H 2 O, [Bi 6 O 4 (OH) 4 (O 3 SNH 2 ) 6 ] and its monohydrate, [Bi 6 O 3 (OC 6 F 5 ) 12 (C 6 H 5 CH 3 )], [Bi 8 O 4 { t BuC8} 2 ] ( t BuC8 = p ‐ tert ‐butylcalix[8]arene), and [Bi 9 O 7 (hfac) 13 ] (hfac = hexafluoroacetylacetonate) . Additionally, bismuth oxido clusters with high nuclearities such as [Bi 34 O 22 (BHA) 22 ( H ‐BHA) 14 (dmso) 6 ] ( H 2 BHA = benzohydroxamic acid), [Bi 38 O 45 (hfac) 24 ], [{Bi 38 O 45 (NO 3 ) 24 (dmso) 26 } · 4dmso][{Bi 38 O 45 (NO 3 ) 24 (dmso) 24 } · 4dmso], and [Bi 38 O 45 (OMc) 24 (dmso) 9 ] · 2dmso · 7H 2 O have been presented.…”