The chemistry of 3-mercapto-1-propanol with group 4 metallocene derivatives. The molecular structure of Cp2∗ZrCl(OCH2CH2CH2SH)
摘要:
Titanocene or permethylzirconocene dichloride reacts with 1 molar equivalent of 3-mercapto-1-propanol (HOCH2CH2CH2SH) in the presence of NEt(3) to give the monomeric chelate complex Cp(2)Ti(OCH2CH2CH2S) (1) or the oxygen-banded monomeric complex Cp(2)*ZrCl(OCH2CH2CH2SH) (2), respectively. When Cp(2)*Zr(CH3)(2) reacts with 1 molar equivalent of HOCH2CH2CH2SH, the oxygen-bonded monomeric complex Cp(2)*Zr(CH3)(OCH2CH2CH2SH) (3) is obtained first. The complex 3 loses the methane extremely slowly to give the monomeric chelate complex Cp(2)*Zr(OCH2CH2CH2S) (4). However, the addition of HNEt(3)Cl to a solution of 4 in C6D6 converts 4 to the oxygen-bonded complex 2 in 24 h. The complex 3 can also be converted to 2 by the addition of HNEt(3)Cl with a slower rate of 1 week. The dialkoxy complex Cp(2)*Zr(OCH2CH2CH2SH)(2) (5) is obtained from the reaction of Cp(2)*Zr(CH3)(2) in neat HOCH2CH2CH2SH. The complex 2 crystallizes in the monoclinic P2(1)/c space group with cell parameters a = 9.128(2) Angstrom, b = 16.276(2) Angstrom, c = 16.141(3) Angstrom, beta = 93.75(2)degrees, and z = 4 with R = 0.040 and R(w) = 0.049. The molecular structure of 2 shows a short Zr-O distance at 1.930(3) Angstrom and a large Zr-O-C(21) angle at 172.5(3)degrees which are indications of strong Zr-O pi bonding.