Shortly after the discovery of ferrocene in the early 50 different researchers began looking for other metal sandwich complexes. I just flew kobaltoceny, wanadoceny etc. Interestingly, we found that this type of connection can also create main group elements, including magnesium.
Magnezocen (actually bis (cyclopentadienyl) magnesium ) was synthesized for the first time independently by Cotton and Wilkinson and Fischer and Hafner in 1954 year. The diagram below shows two possible routes of synthesis
MGCP 2 is a crystalline , piroforycznym a solid white color. It is soluble in polar solvents and nonpolar. It is very sensitive to moisture, is rapidly hydrolysed to Mg (OH) 2 and cyclopentadiene . Case type bonds in the molecule magnezocenu was (and still is actually) the issue of debate. The fact that MGCP 2 shows structural similarity to the ferrocene, and has no dipole moment does not show clearly the nature of covalent bonds. If we assume a purely ionic nature of the interactions, sandwich structure magnezocenu would be beneficial in view of electrostatic interactions. The high polarity bonds in magnezocenie also shows some experimental data, such as electrical conductivity in solutions of liquid ammonia and tetrahydrofuran, rapid hydrolysis and the similarity of chemical shift in the spectrum 13 C-NMR shifts of the metal cyklopentadienylkach a group which, as is known, are compounds with the ionic structure [ LiCp d = 103.6 ppm, stoned d = 103.4 ppm, MGCP 2 d = 108.0 ppm , while for covalent FeCp 2 d = 68.2 ppm]. On the other hand, the data resulting from studies of solutions of Cp 2 Mg nonpolar solvents using spectroscopic 25 Mg-NMR (Small signal width at half maximum for the spectrum performed in toluene at room temperature, d = -85.4 ppm In ½ = 150 Hz) indicate the nature of covalent bonds.
Magnezocen is used in the synthesis of other sandwich complexes and in the process of p-doping of GaN and AlInGaP (Aluminum indium gallium phosphide).
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