cis- and trans-Dichloro-derivatives of six- and seven-co-ordinate zirconium and hafnium bonded to quadridentate Schiff-base ligands. Crystal structures of [Zr(acen)Cl2(thf)], [M(salphen)Cl2(thf)]·0.5thf, [M(acen)Cl2], (M = Zr or Hf), and [Zr(msal)Cl2][acen =N,N′-ethylenebis(acetylacetoneiminate), sa
cis- and trans-Dichloro-derivatives of six- and seven-co-ordinate zirconium and hafnium bonded to quadridentate Schiff-base ligands. Crystal structures of [Zr(acen)Cl2(thf)], [M(salphen)Cl2(thf)]·0.5thf, [M(acen)Cl2], (M = Zr or Hf), and [Zr(msal)Cl2][acen =N,N′-ethylenebis(acetylacetoneiminate), sa
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DOI：
10.1039/dt9900001335
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发表时间：
1990
期刊：
影响因子：
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通讯作者：
Fabio Corazza;E. Solari;C. Floriani;A. Chiesi-Villa;C. Guastini
中科院分区：
文献类型：
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作者：
Fabio Corazza;E. Solari;C. Floriani;A. Chiesi-Villa;C. Guastini
MCl4·2thf(四氢呋喃=四氢呋喃)与四齿席夫碱的钠盐[L=N，N‘-亚乙基双(乙酰丙酮亚胺)(ACEN)，N，N’-亚乙基双(水杨叉亚胺)(Salen)，N，N′-ethylenebis(α-methylsalicylideneiminate)(dmsalen)，或N，N′-o-phenylenebis(salicylideneiminate)(salphen)]]反应生成[MLCl2(四氢呋喃)]。X-射线分析表明，所有的金属离子都是七配位的，具有伪五方双锥几何结构。详细地报道了[Zr(Acen)Cl2(THF)](5)，[Zr(Salphen)Cl2(THF)]·0.5thf(10)的结构，以及相应的等结构Hf配合物[HF(Salphen)Cl2(THF)]·0.5thf(11)的结构。双锥体的赤道平面由N2O2施主原子和来自四氢呋喃的氧原子定义，而两个氯原子相互转化[Cl-Zr-Cl 169.1(1)，(5)；165.2(1)，(10)；Cl-Hf-Cl 166.3(1)，(11)]。由甲苯重结晶的七配位络合物除去了四氢呋喃，生成了六配位络合物。同构体[Zr(Acen)Cl2](12)和[Hf(Acen)Cl2](13)的结构测定表明，金属与两个氯配位，呈顺式排列[Cl-Zr-Cl87.2(1)，(12)；Cl-Hf-Cl87.4(1)°，(13)]。在六配位络合物中，配位球内的键长明显较短。顺式和反式异构体在非配位溶剂的溶液中不能相互转化，如C6H6或CH2Cl2，如其独特的1H n.m.r所示。光谱。在没有几何约束的情况下，锆(IV)更倾向于氯化配体的六配位和顺式排列。合成了含双齿席夫碱配体的[Zr(Msal)2Cl2](15)(msal=N-甲基水杨亚胺)，[Cl-Zr-Cl97.9(1)°]。它由四氢呋喃结晶而成，形成了无溶剂的六配位形式。晶体结构：配合物(5)，空间群P，a=8.401(1)，b=15.987(2)，c=7.805(1)A，α=98.41(1)，β=90.32(1)，γ=76.65(1)°，Z=2，R=0.042；(10)，空间群P，a=12.759(2)，b=13.332(2)，c=7.587(1)A，α=91.60(2)，β=98.45(1)，γ=85.30(1)°，Z=2，R=0.033；(11)，空间群P，a=12.737(7)，b=13.269(7)，c=7.564(4)A，α=91.48(1)，β=98.56(1)，γ=85.26(1)°Z=2，R 0.027；(12)，空间群P21/n，a=24.150(5)，b=9.160(2)，c=7.282(1)A，β=90.9(1)°，Z=4，R 0.034；(13)，空间群P21/n，a=24.096(10)，b=9.161(4)，c=7.262(3)A，β=90.87(1)°，Z=4，R 0.024；(15)，空间群P，a=13.024(3)，b=14.522(3)，c=9.797(2)A，α=90.10(1)，β=93.14(1)，γ=96.09(1)°，Z=4，R 0.044。
The reaction of MCl4·2thf (thf = tetrahydrofuran) with the sodium salt of quadridentate Schiff bases [L =N,N′-ethylenebis(acetylacetoneiminate)(acen), N,N′-ethylenebis(salicylideneiminate)(salen), N,N′-ethylenebis(α-methylsalicylideneiminate)(dmsalen), or N,N′-o-phenylenebis(salicylideneiminate)(salphen)] yields the complexes [MLCl2(thf)]. X-Ray analyses showed for all of them that the metal ion is seven-co-ordinate with a pseudo-pentagonal bipyramidal geometry. Details of the structures of [Zr(acen)Cl2(thf)](5), [Zr(salphen)Cl2(thf)]·0.5thf (10), and of the corresponding isostructural hafnium complex [Hf(salphen) Cl2(thf)]·0.5thf (11) are reported. The equatorial plane of the bipyramid is defined by the N2O2 donor atoms and by the oxygen atom from thf, while the two chlorine atoms are trans to each other [Cl–Zr–Cl 169.1 (1), (5); 165.2(1), (10); Cl–Hf–Cl 166.3(1)°, (11)]. Recrystallization of the seven-co-ordinate complexes from toluene removed the thf leading to six-co-ordinate complexes. The structural determination of the isostructural [Zr(acen)Cl2](12) and [Hf(acen)Cl2](13) showed the six-co-ordination of the metal with the two chlorines assuming a cis arrangement [Cl–Zr–Cl 87.2(1), (12); Cl–Hf–Cl 87.4(1)°, (13)]. Bond lengths within the co-ordination sphere are significantly shorter in the six-co-ordinate complexes. The cis and trans isomers do not interconvert in solutions of non-co-ordinating solvents, i.e. C6H6 or CH2Cl2, as shown by their distinctive 1H n.m.r. spectra. In the absence of geometrical constraints zirconium(IV) prefers six-co-ordination and a cis arrangement of the chloride ligands. This was confirmed by synthesizing [Zr(msal)2Cl2](15)(msal =N-methylsalicylideneiminate), [Cl–Zr–Cl 97.9(1)°] containing a bidentate Schiff-base ligand. Its crystallization from thf gave the unsolvated six-co-ordinated form. Crystallographic details: complex (5), space group P, a= 8.401 (1), b= 15.987 (2), c= 7.805(1)A, α= 98.41 (1), β= 90.32(1), γ= 76.65(1)°, Z= 2, and R 0.042 for 3 713 observed reflections; (10), space group P, a= 12.759(2), b= 13.332(2), c= 7.587(1)A, α= 91.60(2), β= 98.45(1), γ= 85.30(1)°, Z= 2, and R 0.033 for 3 813 observed reflections; (11), space group P, a= 12.737(7), b= 13.269(7), c= 7.564(4)A, α= 91.48(1), β= 98.56(1), γ= 85.26(1)°Z= 2, and R 0.027 for 4 227 observed reflections; (12), space group P21/n, a= 24.150(5), b= 9.160(2), c= 7.282(1)A, β= 90.90(1)°, Z= 4, and R 0.034 for 1 894 observed reflections; (13), space group P21/n, a= 24.096(10), b= 9.161 (4), c= 7.262(3)A, β= 90.87(1)°, Z= 4, and R 0.024 for 2 124 observed reflections; (15), space group P, a= 13.024(3), b= 14.522(3), c= 9.797(2)A, α= 90.10(1), β= 93.14(1), γ= 96.09(1)°, Z= 4, and R 0.044 for 3 294 observed reflections.