Selenium coronands: synthesis and conformational analysis

Conformational studies on [16]aneS4. Structures of α- and β-[16]aneS4 ([16]aneS4 = 1,5,9,13-tetrathiacyclohexadecane)

“…However, since all the S atoms in (Admans, Cooper & Rawle, 1988). A preliminary refinement of a badly disordered singlecrystal structure implied that [16]aneSe4, the tetraselena analogue of [16]aneS4, adopts a rectangular [3535] conformation in the solid state (Batchelor, Einstein, Gay, Gu, Johnston & Pinto, 1989). The crystal packing in the a and/3 polymorphs is shown in Figs.…”

Stepwise synthesis of selenium coronands containing an odd number of selenium atoms: 1,5,9-triselenacyclododecane and 1,5,9,13,17-pentaselenacycloeicosane

“…Since our initial disclosure, we have reported the one-step syntheses of other prototype selenium coronands (6) and there There have been relatively few reports of the synthesis of selehave been reported syntheses of other macrocyclic diselena nium cOrOnands. the best Our prior Our ethers (7), selenium porphyrin derivatives (8), tetraselena-3.4-report of the serendipitous discovery of the simple selenium benzocyclooctadecane, (9) mixed selena oxa macrocyclic coronands in 1988 (1,2), the only macrocyclic seleno ethers ethers (9)(10)(11)(12), and a tetraselenacyclohexadecine bis-naphthareported were the cyclic oligomers of selenaformaldehyde (3), lene derivative (13).…”

Selenoether macrocyclic chemistry–syntheses and ligand properties of new small-ring Se3- and Se2N-donor macrocycles

“…1−3 Despite significant progress in thioether macrocyclic chemistry, macrocycles involving the heavier selenoether and telluroether functions are much less well developed -especially potentially tridentate small rings. 2,3,5 Synthetic routes to tetraselena-and hexaselena crowns were originally reported by Pinto et al [6][7][8] and the coordination chemistry of especially [16]aneSe 4 (1,5,9,13-tetraselenacyclohexadecane) and to a lesser extent [24]aneSe 6 (1,5,9,13,17,21-hexaselenacyclotetracosane) have been developed with both d-block and p-block elements. 5,[9][10][11][12] The macrocyclic framework facilitates stabilization of unusual species such as [CrX 2 ([16]aneSe 4 )]PF 6 (X = Cl, Br or I), [NiX 2 ([16]aneSe 4 )] containing the hard, oxo-philic d 3 Cr(III) and labile d 8 Ni(II) ions respectively, 9,10 within a selenium-rich coordination environment, and trans-[PtX 2 ([16]aneSe 4 )](PF 6 ) 2 (X = Cl or Br) based upon distorted octahedral Se 4 X 2 coordinated Pt(IV).…”

“…2,3,5 Synthetic routes to tetraselena-and hexaselena crowns were originally reported by Pinto et al [6][7][8] and the coordination chemistry of especially [16]aneSe 4 (1,5,9,13-tetraselenacyclohexadecane) and to a lesser extent [24]aneSe 6 (1,5,9,13,17,21-hexaselenacyclotetracosane) have been developed with both d-block and p-block elements. 5,[9][10][11][12] The macrocyclic framework facilitates stabilization of unusual species such as [CrX 2 ([16]aneSe 4 )]PF 6 (X = Cl, Br or I), [NiX 2 ([16]aneSe 4 )] containing the hard, oxo-philic d 3 Cr(III) and labile d 8 Ni(II) ions respectively, 9,10 within a selenium-rich coordination environment, and trans-[PtX 2 ([16]aneSe 4 )](PF 6 ) 2 (X = Cl or Br) based upon distorted octahedral Se 4 X 2 coordinated Pt(IV). 11 The only known examples of Se 3 macrocycles are [12]aneSe 3 , 13 a naphthyl based Se 3 -donor ring 14 and Me 6 [12]aneSe 3 , 15 the latter obtained via catalytic cyclooligomerisation of 3,3-dimethylselenetane using rhenium carbonyl species.…”

“…5,[9][10][11][12] The macrocyclic framework facilitates stabilization of unusual species such as [CrX 2 ([16]aneSe 4 )]PF 6 (X = Cl, Br or I), [NiX 2 ([16]aneSe 4 )] containing the hard, oxo-philic d 3 Cr(III) and labile d 8 Ni(II) ions respectively, 9,10 within a selenium-rich coordination environment, and trans-[PtX 2 ([16]aneSe 4 )](PF 6 ) 2 (X = Cl or Br) based upon distorted octahedral Se 4 X 2 coordinated Pt(IV). 11 The only known examples of Se 3 macrocycles are [12]aneSe 3 , 13 a naphthyl based Se 3 -donor ring 14 and Me 6 [12]aneSe 3 , 15 the latter obtained via catalytic cyclooligomerisation of 3,3-dimethylselenetane using rhenium carbonyl species. Recently we have reported routes to tridentate mixed S/Te macrocycles and tridentate and hexadentate O/Te and O/Se macrocyclic ligands.…”