Abstract：
Herein we have evidenced the formation of favorable π-hole Br···metal noncovalent interactions (NCIs) involving elements from groups 9, 11 and 12. More in detail, M (M = Co2+, Ni2+, Cu2+ and Zn2+) containing porphyrins have been synthesized and their supramolecular assemblies structurally characterized by means of single crystal X-ray diffraction and Hirshfeld surface analyses, revealing the formation of directional Br···M contacts in addition to ancillary hydrogen bond and lone pair-π bonds. Computations at the PBE0-D3/def2-TZVP level of theory revealed the π-hole nature of the Br···M interaction. In addition, the physical nature of these NCIs was studied using Quantum Chemistry methodologies, providing evidence of π-hole Spodium and Regium bonds in Zn2+ and Cu2+ porphyrins, in addition to unveiling the presence of a π-hole for group 9 (Co2+). On the other hand, group 10 (Ni2+) acted as both electron donor and acceptor moiety without showing an electropositive π-hole. Owing to the underexplored potential of π-hole interactions in transition metal chemistry, we believe the results reported herein will be useful in supramolecular chemistry, organometallics, and solid-state chemistry by i) putting under the spotlight the π-hole chemistry involving first row transition metals and ii) unlocking a new tool to direct the self-assembly of metalloporphyrins.
摘要：
在此，我们已经证明了有利的π-孔Br···金属非共价相互作用（NCI）的形成，涉及第9、11和12族元素。更详细地说,M(M=Co2+,Ni2+,已合成了含Cu2和Zn2）的卟啉，并通过单晶X射线衍射和Hirshfeld表面分析对其结构进行了表征，除了辅助氢键和孤对键外，还揭示了定向Br··M接触的形成。在PBE0-D3/def2-TZVP理论水平上的计算揭示了Br···M相互作用的π孔性质。此外,使用量子化学方法研究了这些NCI的物理性质，提供了Zn2+和Cu2+卟啉中π-孔Spedium和Regium键的证据，除了揭示第9组（Co2）的π孔的存在。另一方面,第10组（Ni2）同时充当电子供体和受体部分，而不显示正电子π-空穴。由于过渡金属化学中π-空穴相互作用的潜力不足，我们相信本文报道的结果将在超分子化学中有用，有机金属化合物,和固态化学，即i）将涉及第一行过渡金属的π孔化学置于聚光灯下，以及ii）解锁一种新工具以指导金属卟啉的自组装。
