Role of axial base coordination in isonitrile binding and chalcogen atom transfer to vanadium(III) complexes.
Role of axial base coordination in isonitrile binding and chalcogen atom transfer to vanadium(III) complexes.
复制标题
轴向碱配位在异腈结合和硫族原子转移到钒（III）络合物中的作用。
作者：
Subhojit Majumdar;Julia M. Stauber;Taryn D. Palluccio;Xiaochen Cai;Alexandra Velian;E. Rybak;M. Temprado;B. Captain;C. Cummins;C. Hoff
氧原子转移到V的焓[（Me 3SiNCH 2CH 2）3 N]，1，形成OV[（Me_3SiNCH_2CH_2）_3N]，1-O，以及硫原子转移（SAT）到1和V的能力（N[t-Bu]Ar）3，2（Ar = 3，5-C6 H3 Me 2），形成相应的硫化物SV[用dbabhNO（dbabhNO = 7-亚硝基-2，3：5，6-二苯并-7-氮杂双环[2.2.1]庚-2，5-二烯）和Ph_3SbS作硫属元素原子转移试剂，在甲苯溶液中，用溶液量热法测定了[（Me_3SiNCH_2CH_2）_3N]、1-S和SV（N[t-Bu]Ar）_3，2-S的含量。1-O中的V-O BDE比2-O中的低6.3 ± 3.2 kcal·mol（-1），1-S中的V-S BDE比2-S中的低3.3 ± 3.1 kcal·mol（-1）。这些差异主要归因于氧化时存在于1的络合物中的V-N轴键的弱化。用低温停流动力学研究了1与dbabhNO的反应速率。OAT的速率常数是2的20倍以上。金刚烷基异腈（AdNC）快速定量结合1和2，形成V（III）的高自旋加合物。在甲苯溶液中，配体对1和2的加成反应速率分别为-19.9 ± 0.6和-17.1 ± 0.7kcal·mol（-1）。与2相比，向1添加更多放热配体与对OAT和SAT观察到的相反。这归因于与硫族元素原子转移相反的配体结合中的V-N轴键的减弱较少，并且与结构数据和计算一致。1，1-O，1-S，1-CNAd和2-CNAd的结构已通过X射线晶体学测定并报道。
The enthalpy of oxygen atom transfer (OAT) to V[(Me3SiNCH2CH2)3N], 1, forming OV[(Me3SiNCH2CH2)3N], 1-O, and the enthalpies of sulfur atom transfer (SAT) to 1 and V(N[t-Bu]Ar)3, 2 (Ar = 3,5-C6H3Me2), forming the corresponding sulfides SV[(Me3SiNCH2CH2)3N], 1-S, and SV(N[t-Bu]Ar)3, 2-S, have been measured by solution calorimetry in toluene solution using dbabhNO (dbabhNO = 7-nitroso-2,3:5,6-dibenzo-7-azabicyclo[2.2.1]hepta-2,5-diene) and Ph3SbS as chalcogen atom transfer reagents. The V-O BDE in 1-O is 6.3 ± 3.2 kcal·mol(-1) lower than the previously reported value for 2-O and the V-S BDE in 1-S is 3.3 ± 3.1 kcal·mol(-1) lower than that in 2-S. These differences are attributed primarily to a weakening of the V-Naxial bond present in complexes of 1 upon oxidation. The rate of reaction of 1 with dbabhNO has been studied by low temperature stopped-flow kinetics. Rate constants for OAT are over 20 times greater than those reported for 2. Adamantyl isonitrile (AdNC) binds rapidly and quantitatively to both 1 and 2 forming high spin adducts of V(III). The enthalpies of ligand addition to 1 and 2 in toluene solution are -19.9 ± 0.6 and -17.1 ± 0.7 kcal·mol(-1), respectively. The more exothermic ligand addition to 1 as compared to 2 is opposite to what was observed for OAT and SAT. This is attributed to less weakening of the V-Naxial bond in ligand binding as opposed to chalcogen atom transfer and is in keeping with structural data and computations. The structures of 1, 1-O, 1-S, 1-CNAd, and 2-CNAd have been determined by X-ray crystallography and are reported.
影响因子：
2.9
作者：
Kharitonov, VG;Sharma, VS;Koesling, D
通讯作者：
Koesling, D
影响因子：
2.9
作者：
Liao, Meng-Sheng;Huang, Ming-Ju;Watts, John D.
通讯作者：
Watts, John D.
在肠沙门氏菌ATP的活性部位：CO（i）rrinoid腺基转移酶的活性部位中四坐标蛋白（II）alamin形成机制的结构见解：残基PHE91和TRP93的关键作用的关键作用。
影响因子：
2.9
作者：
Moore TC;Newmister SA;Rayment I;Escalante-Semerena JC
通讯作者：
Escalante-Semerena JC