The novel phosphonyl-substituted ferrocene derivatives [Fe(η(5) -Cp)(η(5) -C5 H3 {P(O)(O-iPr)2 }2 -1,2)] (Fc(1,2) ) and [Fe{η(5) -C5 H4 P(O)(O-iPr)2 }2 ] (Fc(1,1') ) react with SnCl2 , SnCl4 , and SnPh2 Cl2 , giving the corresponding complexes [(Fc(1,2) )2 SnCl][SnCl3 ] (1), [{(Fc(1,1') )SnCl2 }n ] (2), [(Fc(1,1') )SnCl4 ] (3), [{(Fc(1,1') )SnPh2 Cl2 }n ] (4), and [(Fc(1,2) )SnCl4 ] (5), respectively. The compounds are characterized by elemental analyses, (1) H, (13) C, (31) P, (119) Sn NMR and IR spectroscopy, (31) P and (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(1,1') and Fc(1,2) towards tin(II) chloride.

In this contribution we report the synthesis of the novel unsymmetrical ferrocene‐based pincer‐type proligand η5‐CpFeη5‐C5H2‐1‐Br‐2‐PPh2‐5‐CH2NMe2 (1). Its reactivity is demonstrated by isolation of related organotin derivatives η5‐CpFeη5‐C5H2‐1‐SnR3‐2‐PPh2‐5‐CH2NMe2 (3, R = Ph; 4, R = Me). The reactions of compounds 3 and 4 with H2O2 and elemental sulfur gave the corresponding ferrocenylphosphane oxide (5) and the sulfides (6, 7), respectively. Most remarkably, an unprecedented reaction of the organotin derivative 3 with elemental iodine was observed, providing the ammonium salt [η5‐CpFeη5‐C5H2‐1‐SnPh2I‐2‐P(O)Ph2‐5‐CH2NHMe2]I (8). The compounds are characterized by elemental analyses, 1H, 13C, 31P, 119Sn NMR spectroscopy, electrospray ionization mass spectrometry, and single‐crystal X‐ray diffraction analyses (3–8). Also reported are the solid‐state structures of the hydrolysis products [η5‐CpFeη5‐C5H2‐1‐SnPh2(OH)‐2‐P(O)Ph2‐5‐CH2NHMe2]·0.5H2O (9a) and [η5‐CpFeη5‐C5H2‐1‐SnPh(OH)‐2‐P(O)Ph2‐5‐CH2NMe2]2[I3]2 (9b) that were isolated by serendipity.