The coordination capabilities of the pyrazolyl containing ligands pz*(CH2)2NH(CH2)2pz*, pz*(CH2)2NH(CH2)2NH2, pz*(CH2)2S(CH2)2pz* and pz*(CH2)2S(CH2)2NH2
(pz*
= 3,5-Me2pz) towards the synthon (NEt4)2[ReBr3(CO)3]
(1) were studied. Depending on the reaction conditions, neutral or cationic Re(I) tricarbonyl complexes have been isolated: [ReBr(CO)3(κ2-pz*(CH2)2NH(CH2)2pz*)]
(2), [ReBr(CO)3(κ2-pz*(CH2)2S(CH2)2pz*)]
(3)
[Re(CO)3(κ3-pz*(CH2)2NH(CH2)2pz*)]Br (4), [Re(CO)3(κ2-pz*(CH2)2S(CH2)2pz*)MeOH]Br (5), [Re(CO)3(κ3-pz*(CH2)2NH(CH2)2NH2)]Br (6) and [Re(CO)3(κ3-pz*(CH2)2S(CH2)2NH2)]Br (7). Complexes 2–7 have been characterized by the normal techniques, including X-ray crystallographic analysis in the case of 3, 4, 6 and 7. In these complexes the Re atom adopts a distorted octahedral coordination, being one of the triangular faces defined by the three carbonyl groups and the other three remaining coordination positions by the bidentate and the bromide ligands (3), or by the tridentate and neutral pyrazolyl containing ligands (4, 6, 7). Complexes 2–4, 6 and 7 are static in solution and the 1H NMR data indicate clearly a κ2-coordination mode of the ligand in 2 and 3 and a κ3-coordination in 4, 6 and 7, which agrees with the coordination mode found in the solid state. Compound 5 displays a fluxional behaviour in solution as shown by variable temperature 1H NMR studies. No X-ray data exists for this complex but the pattern obtained for the NMR spectrum at 215 K indicates a κ2-coordination mode for the pyrazolyl containing ligand.
含有
吡唑基
配体pz*(
CH2)2NH( )2pz*、pz*( )2NH( )2NH2、pz*( )2S( )2pz*和pz*( )2S( )2NH2(pz* = 3,5-Me2pz)的配位能力针对合成物(NEt4)2[ReBr3(CO)3](1)进行了研究。根据反应条件,已分离出中性或阳离子Re(I)三羰基配合物: [ReBr(CO)3(κ2-pz*( )2NH( )2pz*)](2),[ReBr(CO)3(κ2-pz*( )2S( )2pz*)](3),[Re(CO)3(κ3-pz*( )2NH( )2pz*)]Br(4),[Re(CO)3(κ2-pz*( )2S( )2pz*)MeOH]Br(5),[Re(CO)3(κ3-pz*( )2NH( )2NH2)]Br(6)和[Re(CO)3(κ3-pz*( )2S( )2NH2)]Br(7)。配合物2–7已通过正常技术进行表征,包括在3、4、6和7的情况下进行的X射线晶体学分析。在这些配合物中,Re原子呈现不规则的八面体配位,三个羰基所定义的三角面和其他三个配位位置分别被双齿和
溴离子配体(3)或三齿和中性
吡唑基
配体(4、6、7)占据。配合物2–4、6和7在溶液中是静态的,1H NMR数据清楚地表明了
配体在2和3中的κ2配位模式以及在4、6和7中的κ3配位模式,这与固态中发现的配位模式一致。化合物5在溶液中表现出可变行为,如不同温度下的1H NMR研究所示。该配合物没有X射线数据,但在215 K下获得的NMR谱图模式表明了含
吡唑基
配体的κ2配位模式。