Synthesis, characterization and structural elucidation of water-soluble 1-aminoalkane and α,ω-diaminoalkane complexes of the pentamethylcyclopentadienyliron dicarbonyl cation, [Cp∗(CO)2Fe]+

A series of water-soluble alkylaminopentamethylcyclopentadienyliron dicarbonyl complexes, [Cp∗(CO)2Fe{NH2(CH2)nCH3}]BF4 (n = 2–6; Cp∗ = η5-C5Me5) and the diaminopropane bridged complex, [{Cp∗(CO)2Fe}2{μ-NH2(CH2)3NH2}](BF4)2 have been synthesized and fully characterized. [Cp∗(CO)2Fe{NH2(CH2)5CH3}]BF4 undergoes counteranion exchange with sodium tetraphenylborate in both aqueous and organic media to give water insoluble [Cp∗(CO)2Fe{NH2(CH2)5CH3}]BPh4. The molecular structures for compounds [Cp∗(CO)2Fe{NH2(CH2)3CH3}]BF4 and [{Cp∗(CO)2Fe}2{μ-NH2(CH2)3NH2}](BF4)2 have been determined by single crystal X-ray crystallography and show that they crystallize in the orthorhombic and monoclinic crystal systems, respectively.