Different Complexation Behavior of P-Functionalized Ferrocene Derivatives Towards SnCl sub(2), SnCl sub(4) and SnPh sub(2)Cl sub(2): Auto-ionization and Redox-Type Reactions

The novel phosphonyl-substituted ferrocene derivatives [Fe( eta super(5)-Cp)( eta super(5 )-C sub(5)H sub(3){P( O)(O-iPr) sub(2)} sub(2)-1,2)] (Fc super(1,2)) and [Fe{ eta super(5)-C sub(5)H sub(4)P(O)(O-iPr) sub(2)} sub(2)] (Fc super(1,1')) react with SnCl sub(2), SnCl sub(4), and SnPh sub(2)Cl sub(2), giving the corresponding complexes [(Fc super(1,2)) sub(2)SnCl][Sn Cl sub(3)] (1), [{(Fc super(1,1'))SnCl sub(2)} sub(n)] (2), [(Fc super(1,1'))SnCl sub(4)] (3), [{(Fc super(1,1'))SnPh sub(2)Cl sub(2)} sub(n)] (4), and [(Fc super(1,2))SnCl sub(4)] (5), respectively. The compounds are characterized by elemental analyses, super(1)H, super(13)C, super(31)P, super(119)Sn NMR and IR spectroscopy, super(31)P and super(119)Sn CP-MAS NMR spectroscopy, cyclovoltammetry, electrospray ionization mass spectrometry, and single-crystal as well as powder X-ray diffraction analyses. The experimental work is accompanied by DFT calculations, which help to shed light on the origin for the different reaction behavior of Fc super(1,1') and Fc super(1,2) towards tin(II) chloride. Small change, big difference: Whereas the phosphonyl-substituted ferrocene derivative [Fe( eta super(5)-Cp)( eta super(5 )-C sub(5)H sub(3){P( O)(O-iPr) sub(2)} sub(2)-1,2)] (Fc super(1,2)) reacts with SnCl sub(2) under auto-ionization giving the salt [(Fc super(1,2)) sub(2)SnCl][Sn Cl sub(3)] (1), its closely related analogue [Fe{ eta super(5)-C sub(5)H sub(4)P(O)(O-iPr) sub(2)} sub(2)] (Fc super(1,1')) gives, under the same reaction conditions, the coordination polymer [{(Fc super(1,1'))SnCl sub(2)} sub(n)] (2; see scheme; Cp=Cyclopentadiene).