Tetra‐ and Decanuclear Iron(II) Complexes of Thiacalixarene Macrocycles: Synthesis, Structure, Mössbauer Spectroscopy and Magnetic Properties

Abstract

Compound 1 is a neutral tetranuclear complex and is best described as an iron(II) square sandwiched between two thiacalixarene macrocycles. Each iron centre is six-coordinate in a trigonal-prismatic geometry made up of four phenoxy oxygen atoms plus two sulfur atoms. Compound 2 is a neutral centrosymmetric decanuclear complex and may be viewed as a dimer of double chloro-bridged pentanuclear

Systematic Structural Coordination Chemistry of p‐tert‐Butyltetrathiacalix[4]arene: Further Complexes of Transition‐Metal Ions

“…III species has been obtained here in a crystalline form for the case of M = Fe, although, at least when solvothermal synthesis is utilised, it is also possible to readily obtain polynuclear (tetra-and also decanuclear) Fe II derivatives. [13] All implied protonic hydrogen atoms have been located in the structure determination [on O(131,231) (Table S1)], providing, with one exception, a satisfactory charge balance; the exception arises from the coordination of a pair of unidentate ligands initially ascribed as O-dmf, but found to be disorderly, in a manner suggesting 50 % formate component (presumed to arise from dmf hydrolysis), thus completing the proposed charge balance. As coordination can activate dmf towards hydrolysis, [37] such reactions might have been expected to complicate many of the syntheses described herein but the problem seems generally rare.…”

“…The largest "trans" angle observed is 162.3(2)°, well below the octahedral norm; the smallest [140.1(2)°] is more typically associated with trigonal prismatic stereochemistry, an expectation somewhat fulfilled in the present situation by considering that the pair of sulfur atoms associated with each copper atom lie almost above each other in projection down the molecular axes, and that the oxygen atom pairs viewed similarly would conform, were it not for the consequences of the "pinching" of the calyces described above. (11,13), the smallest trans angle is again close to 144°, involving long Cu-O,S distances, but for Cu (12,14) the angle is smaller (ca. 140°), involving only one long distance (Cu-S); around the Cu 4 O 8 system, large trans angles are subtended by O(151,121,171,141).…”

“…Irregularities are found among the other associated structural parameters (Tables S1, S8): Ni-S range between 2.3611(6)-3.2540(6) Å and Ni-(µ-O) between 1.963(1)-2.102(1) Å, the latter (longest) distance being associated with the long [3.6198(4) Å] edge of the Ni 4 "square". The (remarkably) long Ni-S distance [3.2540(6) Å], Ni(3)··· S (13), is associated with a nickel atom environment in which the angular geometries are far from orthogonal, and this nickel atom, unlike the other three, may perhaps more properly be considered five-rather than six-coordinate. These perturbations are reflected in other ligand parameters (Table S1).…”

“…To extend the characterisation of this field of coordination chemistry, we have endeavoured (as have others [2,[12][13][14] ) to study a selection of derivatives involving both early members and those in oxidation states other than (II), though for us this has met…”

Cation binding by thiacalixthianthrenes

“…Thiacalixarenes, in which a sulfur bridge replaces the methylene link of calixarenes themselves, have but recently become accessible [6] although there has now been a decade of active research concerning their use for similar applications [7][8][9][10][11][12]. Particular interest in thiacalixarenes has arisen for specific applications in optical materials technology and coordination chemistry due to the unique properties and strong coordinating ability of these macrocycles [13][14][15][16][17][18]. Recently, the synthesis of a new, related class of macrocycles, the thiacalixthianthrenes [19,20], has been reported.…”