Department of Chemistry, Section of Inorganic and Analytical Chemistry, University of Ioannina, 45110, Greece.
Inorg Chem. 2010 Jan 4;49(1):52-61. doi: 10.1021/ic901809f.
Reaction of the N,N-disubstituted bis-(hydroxylamino) ligand 2,6-bis[hydroxy(methyl)amino]-4-morpholino-1,3,5-triazine, H(2)bihyat, with V(IV)OSO(4).5H(2)O in water for 6 h followed by the addition of methyl alcohol resulted in the isolation of the unsymmetrical mu-oxido divanadium(V) compound [V(V)(2)O(2)(mu(2)-O)(bihyat)(hyta)(hyto)].3H(2)O (1.3H(2)O) and of the methylhydroxylamido derivative [V(V)O(bihyat)(CH(3)NHO)].H(2)O (2.H(2)O). The N,N-disubstituted mono(hydroxylamino) ligands Hhyta, Hhyto, and CH(3)NHOH were formed by the decomposition of the ligand H(2)bihyat in the presence of vanadium. The structures of compounds 1.3H(2)O and 2.H(2)O were determined by X-ray crystallography. The structure of 1.3H(2)O consists of one five-coordinate vanadium(V) atom and one six-coordinate vanadium(V) atom bridged by an oxido group and ligated to a tridentate bihyat(2-) and two bidentate hyta(-) and hyto(-) ligands, respectively. The two terminal oxido groups in 1.3H(2)O are syn-directed, lying on the same side of the V-O-V plane. The coordination environment of the vanadium atom in 2.H(2)O approximates to a highly distorted pentagonal pyramid with the oxido ligand occupying the apical position. Compounds 1.3H(2)O and 2.H(2)O were studied by multinuclear NMR ((1)H, (13)C, and (51)V) to elucidate their solution structures. The (51)V NMR of 1.3H(2)O in anhydrous CD(2)Cl(2) gave two signals at -199 and -508 ppm, which were assigned to the five- and six-coordinate vanadium(V) atoms, respectively. The resonance of the five-coordinate vanadium nucleus, in a field much lower than that expected from Rehder's [Inorg. Chem., 1988, 27, 584-587] referencing scale, was attributed to the low-energy ligand-to-metal charge transfer transition at 605 nm [epsilon(M) = 5050 M(-1) cm(-1)] of 1.3H(2)O according to Pecoraro et al. [J. Am. Chem. Soc., 1992, 114, 9925-9933]. Electrospray ionization-mass spectrometry studies were used to follow the decomposition products of H(2)bihyat in the presence of vanadium.
反应的 N，N- 取代双-（羟氨基）配体 2,6-双[羟基（甲基）氨基]-4-吗啉-1,3,5-三嗪，H（2）bihyat，与 V（IV）OSO（4）.5H（2）O 在水中 6 小时后加入甲醇，分离出不对称的 μ-氧代二钒（V）化合物 [V（V）（2）O（2）（μ（2）-O）（bihyat）（hyta）（hyto）].3H（2）O（1.3H（2）O）和甲基羟氨基衍生物 [V（V）O（bihyat）（CH（3）NHO）].H（2）O（2.H（2）O）。在存在钒的情况下，配体 H（2）bihyat 分解形成 N，N- 取代的单（羟氨基）配体 Hhyta、Hhyto 和 CH（3）NHOH。化合物 1.3H（2）O 和 2.H（2）O 的结构通过 X 射线晶体学确定。1.3H（2）O 的结构由一个五配位的钒（V）原子和一个六配位的钒（V）原子组成，由一个氧原子桥接，分别与一个三齿配体 bihyat（2-）和两个二齿配体 hyta（-）和 hyto（-）配位。1.3H（2）O 中的两个末端氧原子是顺式定向的，位于 V-O-V 平面的同一侧。2.H（2）O 中钒原子的配位环境近似于高度扭曲的五角锥，其中氧配体占据顶点位置。通过多核 NMR（（1）H、（13）C 和（51）V）研究了化合物 1.3H（2）O 和 2.H（2）O，以阐明它们的溶液结构。在无水 CD（2）Cl（2）中，1.3H（2）O 的（51）V NMR 给出了两个信号，分别在-199 和-508 ppm 处，分别分配给五配位和六配位的钒（V）原子。五配位钒核的共振，低于 Rehder [Inorg。化学，1988，27，584-587] 参考标度预期的场，归因于 1.3H（2）O 的低能量配体-金属电荷转移跃迁，在 605 nm [epsilon（M）= 5050 M（-1）cm（-1）] 根据 Pecoraro 等人的研究。[J. Am. Chem. Soc.，1992，114，9925-9933]。使用电喷雾电离质谱研究来跟踪 H（2）bihyat 在存在钒的情况下的分解产物。
