Chlorobis(dppe)iron hydride

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Chlorobis(dppe)iron hydride
Names
IUPAC name
Chlorohydridobis(bis-1,2-(diphenylphosphino)ethane)iron(II)
Identifiers
3D model (JSmol)
  • InChI=1S/2C26H24P2.ClH.Fe.H/c2*1-5-13-23(14-6-1)27(24-15-7-2-8-16-24)21-22-28(25-17-9-3-10-18-25)26-19-11-4-12-20-26;;;/h2*1-20H,21-22H2;1H;;/q;;;+1;/p-1
    Key: NSXBDVRBULAONI-UHFFFAOYSA-M
  • Cl[FeH-4]56([P+](c1ccccc1)(c2ccccc2)CC[P+]5(c3ccccc3)c4ccccc4)[P+](c1ccccc1)(c2ccccc2)CC[P+]6(c3ccccc3)c4ccccc4
Properties
C52H49ClFeP4
Molar mass 889.09
Appearance red-violet solid
Melting point 195 °C (383 °F; 468 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Chlorobis(dppe)iron hydride is a coordination complex with the formula HFeCl(dppe)2, where dppe is the bidentate ligand 1,2-bis(diphenylphosphino)ethane. It is a red-violet solid. The compound has attracted much attention as a precursor to dihydrogen complexes.[1]

Structure[edit]

The complex exhibits octahedral molecular geometry. The chloride and hydride ligands are mutually trans.[2] The bond distances between the iron metal atom and the coordinating ligands are given by the following:

Bond Bond distance
Fe-P1 2.238
Fe-P2 2.256
Fe-P3 2.236
Fe-P4 2.255
Fe-Cl 2.404
Fe-H 1.313

Synthesis and reactions[edit]

The compound is synthesized according to the following idealized reaction:[3]

FeCl2 + 2 dppe + Na[BH4] → NaCl + ½ B2H6 + HFeCl(dppe)2
"Top-view" of the structure of HFeCl(dppe)2

In the course of this conversion, high-spin complex FeCl2(dppe)2 converts to low-spin HFeCl(dppe)2.

The complex HFeCl[(dppe)2 exhibits a number of reactions associated with the remaining Fe-Cl bond. Reaction of the complex with sodium borohydride gives the dihydride complex:

HFeCl(dppe)2 + NaBH4 → H2Fe(dppe)2 + NaCl + "BH3"

Removal of chloride using sodium tetrafluorborate under and atmostphere of hydrogen or nitrogen gives the dinitrogen and dihydrogen complexes:[4]

HFeCl(dppe)2 + NaBF4 + N2 → [HFe(N2)(dppe)2]BF4 + NaCl
HFeCl(dppe)2 + NaBF4 + H2 → [HFe(H2)(dppe)2]BF4 + NaCl

References[edit]

  1. ^ Morris RH (2008). "Dihydrogen, Dihydride and in Between: Nmr and Structural Properties of Iron Group Complexes". Coord. Chem. Rev. 2252 (21–22): 2381–2394. doi:10.1016/j.ccr.2008.01.010.
  2. ^ Lee, J.; Jung, G.; Lee, S. W. Structure of trans-chlorohydridobis(diphenylphosphinoethane)iron(II). Bull. Korean. Chem. 1998, 19, 267. ISSN 0253-2964
  3. ^ Giannoccaro, P.; Sacco, A. (1977). "Bis[Ethylenebis(Diphenylphosphine)]‐Hydridoiron Complexes". Inorganic Syntheses. Vol. 17. pp. 69–71. doi:10.1002/9780470132487.ch19. ISBN 9780470132487. {{cite book}}: |journal= ignored (help)
  4. ^ Bautista MT, Bynum LD, Schauer CK (1996). "Synthesis of η2-Dihydrogen Complex, trans-{Fe(η2-H2)(H)[1,2-bis(diphenylphosphino)ethane]2}[BF4]: An Experiment for an Advanced Inorganic Chemistry Laboratory Involving Synthesis and NMR Properties of an η2-H2 Complex". Journal of Chemical Education. 73 (10): 988–991. doi:10.1021/ed073p988.