Structural Aspects of Iron Coordination Compounds: I. Monomeric Derivatives

Abstract

This review summarises almost nine hundred crystallographic structures of monomelic iron coordination compounds. The number of examples per given oxidation state for the iron increases in the order: Fe(-II) (tetrahedral) < Fe(-I) (tetrahedral) < Fe(IV) (six coordinated and square pyramidal) < Fe(0) (five coordinated ) < Fe(I) (square pyramidal and square planar) < Fe(III) (three -to seven coordinated) < Fe(II) (two -to eight and ten coordinated). Variations and trends in bond lengths and angles are discussed. CeHieNeSa bis(S-methylisothiosemicarbazone)2,4-pentanedionate (2-) C9H21N3O9P3 trianion of N,N',N"-tris(dioxophosphorylmethyl)-l,4,7triazacyclononane Ci oH] 2 S 8 tetra(methylthio)tetrathiafulvalenium( 1+) Ci 4H20O 4-tert-butyl-2,6-dimethylacetophenone Ci 4N32N6 1,2-bis( 1,4,7-triaza -1 -cyclononyl)ethane Ci 5H110 2 1,3-diphenyl-l ,3 -propanedionate( 1 -) C15H23N5 2,13 -dimethyl-3,6,9,12,18pentaazabicyclo[12.3.1]octadeca-l(18),2,12,14,16pentaene Ci 5H23S 2,4,6-triisopropylbenzenethiolate( 1 -) Q5H27N5 2,13 -dimethyl-3,6,9,12,18pentaazabicyclo[12.3.1]octadeca(18),14,16-triene C16H13N3O2S dianion of S-methyl-N' ^-bisCsalicylidene) isothiosemicarbazide C16H25N5 2,14-dimethyl -3,6,10,13,19 -pentaazabicyclo [13.3.1] nonadeca-l(19),2,13,15,17-pentaene C16H32N4 5,7,7,12,14,14-hexamethyl-l,4,8,11-tetraazacyclotetra deca-4,11-diene Ci 7H17N5 bis(benzimidazol-2-ylmethyl)methylamine Ci 8 H] 8 N 6 conjugated 14-membered ring of hexaaza ligand C20H14N2O2 2,2'-[o-phenylenebis(nitrilomethylidine)diphenolate-N,N',0,0'(2-) C20H24N2O2 N-n-propylsalicylaldiminate (2-) C21H19N7 cation derived from 1,10-phenanthroline and 2,6pyridine dicarbonyls C22H22N2O2 l,l'-diphenyl-3,3'-(ethylenediimino)di-l-butanonate (2-) C22H20N2O4S dianion of Ν,Ν'-(1,3 -dimethyl-1,3 -diphenyl-2-thiapropyl)-2,3-dihydroxyterephthalic acid amide C22H22N4 7,16-dihydro-6,8,15,17-tetramethyldibenzo[fc,/] [1,4,8,1 l]tetraazacyclotetradecanate (2-) C22H25O6 atrovenetin orange trimethyl ether C22H34N4O5 macrocyclic tetraamide C23H21N7 quinquedentate macrocyclic ligand C23H25N7O2 6,13 -(bis-2-hydroxyethyl)-6H, 13H-tripyrido[cd,fg,lm] -[1,2,4,7,9,10,13] heptaaza-pentadecine C24H36N12 1,4,7,10-tetrakis(pyrazol-l-ylmethyl)-l,4,7,10tetraazacyclododecane 59

Effects of Temperature and Pressure on the Mössbauer Spectra of Models for the [4Fe-4S]2+Clusters of Iron−Sulfur Proteins and the Structure of [PPh4]2[Fe4S4(SCH2CO2C2H5)4]

“…82). The tetrahedron forming this inner core is among the most nearly regular so far found . The tetrahedron of the iron atoms is very slightly elongated along the c axis, contrasting with a slight flattening of the associated S(2) tetrahedron .…”

(THF)3LiCl as a Ligand for Low-Coordinate Fe(II): Crystal Structure of [(Me3Si)2N]2Fe(μ-Cl)Li(THF)3

“…The Li-O distances range from 190.6(13) to 194.1( 14) pm (average, 192.0 pm), as is typical for tetracoordinate Li + . 17 The Li-Cl distance is 234.5- (13) pm. These values are very similar to those found for the contact ion pairs LiCl(H 2 O)(C 5 H 5 N) 2 18 and LiI(THF) 3 19 (after ionic radius correction).…”

“…11 The three-coordinated anionic complexes {M[N(SiMe 3 ) 2 ] 3 }are known for both iron and cobalt and may be rationalized as adducts of M[N(SiMe 3 ) 2 ] 2 with the very strong base [N(SiMe 3 ) 2 ] -. 12 To date, only four examples of structurally characterized monomeric complexes containing three-coordinate iron are known, 13 viz. {Fe[N(SiMe 3 ) 2 ] 3 } n-(n ) 0, 14 1 12 ), (THF)Fe-[N(SiMe 3 ) 2 ] 2 , 9 and {ClFe[Si(SiMe 3 ) 3 ] 2 } -.…”

“…To date, only four examples of structurally characterized monomeric complexes containing three-coordinate iron are known, viz. {Fe[N(SiMe 3 ) 2 ] 3 } n - ( n = 0, 1 12 ), (THF)Fe[N(SiMe 3 ) 2 ] 2 , and {ClFe[Si(SiMe 3 ) 3 ] 2 } - .…”

Mechanism of deactivation processes of excited iron(III) thiocyanato complexes with benacen‐type ligands

“…Single crystal X-ray diffraction investigations related to iron(III) complexes with thiocyanato ligands or benacentype ligands and solution studies show that (i) NCS − anion is coordinated to the Fe(III) central atom through its nitrogen [19]; (ii) benacen-type ligands form the equatorial plane of the complexes and two monodentate ligands are bonded in the axial positions [19]; (iii) in the majority of its high-spin complexes, the central atom Fe(III) is hexacoordinated both in the solid state and solutions [19,20].…”