Schofield A Daniel, Barros Mariana Luna, Cushion Michael G, Schwarz Andrew D, Mountford Philip
Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford, UKOX1 3TA.
Dalton Trans. 2009 Jan 7(1):85-96. doi: 10.1039/b813116c. Epub 2008 Oct 21.
The reaction of bis(3,5-dimethylpyrazolyl)methylphenol N(2)O(Ar)H (1) with NaH in THF formed dimeric Na(kappa(2)-N(2)O(Ar))(THF) (2), which contains a kappa(2)(N,O)-bound bidentate N(2)O(Ar) ligand. The reaction of 1 with Mg(n)Bu(2) gave the four-coordinate monomeric butyl compound Mg(N(2)O(Ar))(n)Bu (3), whereas with (n)BuMgCl, a mixture of products was formed, including the six-coordinate homoleptic species Mg(N(2)O(Ar))(2) (4). The reaction of Na(kappa(2)-N(2)O(Ar))(THF) with (n)BuMgCl also gave 3, as did the redistribution reaction of Mg(n)Bu(2) with 4. The reaction of 1 with Mg{N(SiRMe(2))(2)}(2) afforded the four-coordinate amide derivatives Mg(N(2)O(Ar)){N(SiRMe(2))(2)} (R = Me (6) or H (7)), together with 4. The reactions of 1 with ZnMe(2) or Zn{N(SiMe(3))(2)}(2) gave the monomeric compounds Zn(N(2)O(Ar))Me (8) and Zn(N(2)O(Ar)){N(SiMe(3))(2)} (9), respectively. The reaction 9 of with HCl formed Zn(N(2)O(Ar))Cl (11), and subsequent addition of LiN(SiHMe(2))(2) to 11 led to Zn(N(2)O(Ar)){N(SiHMe(2))(2)} (12). The reaction of 1 with either Zn{N(SiMe(3))(2)}(2) or 9 gave Zn(N(2)O(Ar))(2). The compounds 2, 3, 4, 6, 8, 9 and 11 were crystallographically characterized. Compound was very active for the ring-opening polymerization (ROP) of epsilon-caprolactone (epsilon-CL) but the process was very poorly controlled as judged by the M(n) and polydispersity index of the polymer. Compounds 3, 8, 9 and 12 gave poor conversions to poly(epsilon-CL) over extended periods. N(2)O(Ar)H = 2,4-di-tert-butyl-6-(bis(3,5-dimethylpyrazolyl)methyl)phenol.
双(3,5 - 二甲基吡唑基)甲基苯酚N(2)O(Ar)H (1)与NaH在四氢呋喃(THF)中反应生成二聚体[Na(κ(2)-N(2)O(Ar))(THF)]₂ (2)，其包含一个以κ(2)(N,O)键合的双齿N(2)O(Ar)配体。1与Mg(n)Bu₂反应得到四配位单体丁基化合物Mg(N(2)O(Ar))(n)Bu (3)，而与(n)BuMgCl反应则形成产物混合物，包括六配位的同配物种Mg(N(2)O(Ar))₂ (4)。[Na(κ(2)-N(2)O(Ar))(THF)]₂与(n)BuMgCl反应也生成3，Mg(n)Bu₂与4的再分配反应同样如此。1与Mg{N(SiRMe₂)₂}(2)反应得到四配位酰胺衍生物Mg(N(2)O(Ar)){N(SiRMe₂)₂} (R = Me (6) 或 H (7))，同时还生成4。1与ZnMe₂或Zn{N(SiMe₃)₂}(2)反应分别得到单体化合物Zn(N(2)O(Ar))Me (8) 和Zn(N(2)O(Ar)){N(SiMe₃)₂} (9)。9与HCl反应生成Zn(N(2)O(Ar))Cl (11)，随后向11中加入LiN(SiHMe₂)₂得到Zn(N(2)O(Ar)){N(SiHMe₂)₂} (12)。1与Zn{N(SiMe₃)₂}(2)或9反应均生成Zn(N(2)O(Ar))₂。化合物2、3、4、6、8、9和11通过晶体学进行了表征。化合物对ε - 己内酯(ε - CL)的开环聚合(ROP)非常活跃，但从聚合物的数均分子量(Mn)和多分散指数判断，该过程的控制效果很差。化合物3、8、9和12在较长时间内对聚(ε - CL)的转化率很低。N(2)O(Ar)H = 2,4 - 二叔丁基 - 6 - (双(3,5 - 二甲基吡唑基)甲基)苯酚。
