Młodzianowska Anna, Latos-Grazyński Lechosław, Szterenberg Ludmiła, Stepień Marcin
Department of Chemistry, University of Wrocław, 14 F. Joliot-Curie Street, Wrocław 50 383, Poland.
Inorg Chem. 2007 Aug 20;46(17):6950-7. doi: 10.1021/ic700647v. Epub 2007 Jul 17.
Boron(III) has been inserted into N-confused porphyrin, (NCPH)H2 (1), and N-fused porphyrin, (NFP)H (2). The reaction of dichlorophenylborane and 1 yields sigma-phenylboron N-confused porphyrin (4). The boron atom is bound by two pyrrolic nitrogen atoms and the sigma-phenyl ligand. The N-confused pyrrole ring is not involved in the direct coordination because the C(21)-H fragment remains intact. A reaction between PhBCl2 and N-fused porphyrin produces sigma-phenylboron N-fused porphyrin (3+). 4 converts quantitatively into 3+ under protonation. In sigma-phenylboron N-fused porphyrin [(NFP)BPh]Cl, the coordinating environment of boron(III) resembles a distorted trigonal pyramid, with the nitrogen atoms occupying equatorial positions and with the phenyl ligand lying at the unique apex. Boron(III) is displaced by 0.547(4) A from the N3 plane. The B-N distances are as follows: B-N(22), 1.559(4) A; B-N(23), 1.552(4) A; B-N(24), 1.568(4) A; B-C(ipsoPh), 1.621(4) A. 3+ can be classified as a boronium cation considering a filled octet and a complete coordination sphere. 3+ is susceptible to alkoxylation at the inner C(9) carbon atom, yielding 5-OR. The addition of acid results in protonation of the alkoxy group and elimination of alcohol, restoring the original 3+. Density functional theory has been applied to model the molecular and electronic structure of 4, 3+, and syn and anti isomers of methoxy adducts 5-OMe.
硼（III）已被插入到N-稠合卟啉（NCPH）H₂（1）和N-并合卟啉（NFP）H（2）中。二氯苯基硼烷与1反应生成σ-苯基硼N-稠合卟啉（4）。硼原子由两个吡咯氮原子和σ-苯基配体配位。N-稠合的吡咯环不参与直接配位，因为C（21）-H片段保持完整。PhBCl₂与N-并合卟啉之间的反应生成σ-苯基硼N-并合卟啉（3⁺）。4在质子化条件下定量转化为3⁺。在σ-苯基硼N-并合卟啉[（NFP）BPh]Cl中，硼（III）的配位环境类似于扭曲的三角锥，氮原子占据赤道位置，苯基配体位于唯一的顶点。硼（III）相对于N3平面位移了0.547（4）Å。B-N距离如下：B-N（22），1.559（4）Å；B-N（23），1.552（4）Å；B-N（24），1.568（4）Å；B-C（ipsoPh），1.621（4）Å。考虑到完整的八隅体和完整的配位球，3⁺可归类为硼鎓阳离子。3⁺在内侧C（9）碳原子处易发生烷氧基化反应，生成5-OR。加入酸会导致烷氧基质子化并消除醇，恢复为原来的3⁺。密度泛函理论已被用于模拟4、3⁺以及甲氧基加合物5-OMe的顺式和反式异构体的分子和电子结构。
