Nieto Sonia, Pérez Julio, Riera Lucía, Riera Víctor, Miguel Daniel, Golen James A, Rheingold Arnold L
Departamento de Química OrgAnica e InorgAnica-IUQOEM, Facultad de Química, Universidad de Oviedo-CSIC, 33006 Oviedo, Spain.
Inorg Chem. 2007 Apr 16;46(8):3407-18. doi: 10.1021/ic0700046. Epub 2007 Mar 17.
Compound cis,fac-[Mo(eta3-allyl)(CO)2(Hdmpz)3]BAr'4 (1) (Hdmpz = 3,5-dimethylpyrazole, Ar' = 3,5-bis(trifluoromethyl)phenyl) undergoes rapid substitution of one of the pyrazole ligands by anions, including the low nucleophilic ReO4-, a reaction that afforded [Mo(OReO3)(eta3-allyl)(CO)2(Hdmpz)2] (2), structurally characterized by X-ray diffraction. The new compounds fac-[Mn(CO)3(Hdmpz)3]BAr'4 (4a) and fac-[Mn(CO)3(HtBupz)3]BAr'4 (4b) (HtBupz = 3(5)-tert-butylpyrazole) also undergo pyrazole substitution with most anions, and the product from the reaction with nitrate was crystallographically characterized. Compounds 4a,b were found to be substitutionally stable toward perrhenate, and the adducts [Mn(CO)3(Hdmpz)3].[ReO4] (7a) and [Mn(CO)3(HtBupz)3].[ReO4].[Bu4N].[BAr'4] (7b), crystallographically characterized, display hydrogen bonds between one of the perrhenate oxygens and the N-H groups of two of the pyrazole ligands. The structurally similar adduct [Re(CO)3(Hdmpz)3].[ReO4] (8) was found to result from the interaction of [Re(CO)3(Hdmpz)3]BAr'4 with perrhenate. The reaction of [Re(OTf)(CO)5] with 3,5-dimethylpyrazole (Hdmpz) afforded [Re(CO)5(Hdmpz)]OTf (9). The reaction of 9 with Hdmpz and NaBAr'4 yielded [Re(CO)4(Hdmpz)2]BAr'4 (10), which was found to be unstable toward chloride anion. In contrast, the new compound fac,cis-[Re(CO)3(CNtBu)(Hdmpz)2]BAr'4 (11) is stable in solution in the presence of different anions. Binding constants for 11 with chloride, bromide, and nitrate are 1-2 orders of magnitude lower than those found for these anions and rhenium tris(pyrazole) hosts, indicating that the presence of the third pyrazole ligand is crucial. Compounds fac-[Re(CO)3(HPhpz)3]BAr'4 (14) (HPhpz = 3(5)-phenylpyrazole) and fac-[Re(CO)3(HIndz)3]BAr'4 (15) (HIndz = indazole) are, in terms of anion binding strength and selectivity, inferior to those with dimethylpyrazole or tert-butylpyrazole ligands.
化合物顺，面式-[Mo(η³-烯丙基)(CO)₂(Hdmpz)₃]BAr'₄ (1)（Hdmpz = 3,5-二甲基吡唑，Ar' = 3,5-双(三氟甲基)苯基）会被包括低亲核性的ReO₄⁻在内的阴离子快速取代其中一个吡唑配体，该反应生成了[Mo(OReO₃)(η³-烯丙基)(CO)₂(Hdmpz)₂] (2)，通过X射线衍射对其结构进行了表征。新化合物面式-[Mn(CO)₃(Hdmpz)₃]BAr'₄ (4a)和面式-[Mn(CO)₃(HtBupz)₃]BAr'₄ (4b)（HtBupz = 3(5)-叔丁基吡唑）也会与大多数阴离子发生吡唑取代反应，并且对与硝酸盐反应的产物进行了晶体学表征。发现化合物4a、b对高铼酸盐具有取代稳定性，晶体学表征的加合物[Mn(CO)₃(Hdmpz)₃].[ReO₄] (7a)和[Mn(CO)₃(HtBupz)₃].[ReO₄].[Bu₄N].[BAr'₄] (7b)在一个高铼酸根氧原子与两个吡唑配体的N - H基团之间显示出氢键。发现结构相似的加合物[Re(CO)₃(Hdmpz)₃].[ReO₄] (8)是由[Re(CO)₃(Hdmpz)₃]BAr'₄与高铼酸盐相互作用产生的。[Re(OTf)(CO)₅]与3,5-二甲基吡唑（Hdmpz）反应生成[Re(CO)₅(Hdmpz)]OTf (9)。9与Hdmpz和NaBAr'₄反应生成[Re(CO)₄(Hdmpz)₂]BAr'₄ (10)，发现其对氯离子不稳定。相比之下，新化合物顺，面式-[Re(CO)₃(CNtBu)(Hdmpz)₂]BAr'₄ (11)在不同阴离子存在下在溶液中是稳定的。11与氯离子、溴离子和硝酸根的结合常数比这些阴离子与铼三(吡唑)主体的结合常数低1 - 2个数量级，表明第三个吡唑配体的存在至关重要。化合物面式-[Re(CO)₃(HPhpz)₃]BAr'₄ (14)（HPhpz = 3(5)-苯基吡唑）和面式-[Re(CO)₃(HIndz)₃]BAr'₄ (15)（HIndz = 吲唑）在阴离子结合强度和选择性方面不如具有二甲基吡唑或叔丁基吡唑配体的化合物。
