Synthesis and structural characterization of rhenium(I) tricarbonyl complexes with 2,6-bis(pyrazol-1-yl)pyridine ligands functionalized with carboxyl (COOH), methoxycarbonyl (COOCH3), and amino (NH2) groups

IF 2.8 3区化学 Q2 CHEMISTRY, INORGANIC & NUCLEAR

Polyhedron Pub Date : 2026-03-01 Epub Date: 2026-01-16 DOI:10.1016/j.poly.2026.117971

Natcha Temnuch , Thinnaphat Poonsawat , Thitiwat Tanyalax , Peerapong Chumkaeo , Teera Chantarojsiri , Khetpakorn Chakarawet , Yumi Yakiyama , Hidehiro Sakurai , Ekasith Somsook

{"title":"Synthesis and structural characterization of rhenium(I) tricarbonyl complexes with 2,6-bis(pyrazol-1-yl)pyridine ligands functionalized with carboxyl (COOH), methoxycarbonyl (COOCH3), and amino (NH2) groups","authors":"Natcha Temnuch , Thinnaphat Poonsawat , Thitiwat Tanyalax , Peerapong Chumkaeo , Teera Chantarojsiri , Khetpakorn Chakarawet , Yumi Yakiyama , Hidehiro Sakurai , Ekasith Somsook","doi":"10.1016/j.poly.2026.117971","DOIUrl":null,"url":null,"abstract":"<div><div>Rhenium(I) tricarbonyl complexes with 2,6-bis(pyrazol-1-yl)pyridine ligands functionalized with <img>COOH, <img>COOCH<sub>3</sub>, and <img>NH<sub>2</sub> were synthesized <em>via</em> UV-induced substitution of Re(CO)<sub>5</sub>Br in acetone under 365 nm irradiation. Single-crystal X-ray diffraction revealed distorted octahedral geometries, with Re<img>N bond lengths of 2.133–2.239 Å, N<img>Re<img>N angles of 73.30–73.98°, and Re<img>Br distances of 2.627–2.642 Å, reflecting the influence of ligand substituents. ATR-IR spectroscopy demonstrated that electron-withdrawing <img>COOH and <img>COOCH<sub>3</sub> groups caused slight blue shifts in <em>ν</em>(CO), whereas <img>NH<sub>2</sub> induced red shifts, consistent with modulation of metal-to-ligand backbonding. UV–Vis studies showed that acetone preserved complex stability, whereas acetonitrile caused significant destabilization. Variable-temperature <sup>1</sup>H/<sup>13</sup>C NMR confirmed stable bidentate coordination in solution. DFT calculations revealed that electron-withdrawing groups lowered LUMO energies, while electron-donating group raised HOMO levels, tuning charge-transfer behavior. ESI-MS and elemental analyses confirmed molecular purity. These results indicate that functionalization of ligands enables precise control over rhenium(I) structural and electronic properties.</div></div>","PeriodicalId":20278,"journal":{"name":"Polyhedron","volume":"287 ","pages":"Article 117971"},"PeriodicalIF":2.8000,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Polyhedron","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0277538726000173","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2026/1/16 0:00:00","PubModel":"Epub","JCR":"Q2","JCRName":"CHEMISTRY, INORGANIC & NUCLEAR","Score":null,"Total":0}

引用次数: 0

Abstract

Rhenium(I) tricarbonyl complexes with 2,6-bis(pyrazol-1-yl)pyridine ligands functionalized with COOH, COOCH₃, and NH₂ were synthesized via UV-induced substitution of Re(CO)₅Br in acetone under 365 nm irradiation. Single-crystal X-ray diffraction revealed distorted octahedral geometries, with ReN bond lengths of 2.133–2.239 Å, NReN angles of 73.30–73.98°, and ReBr distances of 2.627–2.642 Å, reflecting the influence of ligand substituents. ATR-IR spectroscopy demonstrated that electron-withdrawing COOH and COOCH₃ groups caused slight blue shifts in ν(CO), whereas NH₂ induced red shifts, consistent with modulation of metal-to-ligand backbonding. UV–Vis studies showed that acetone preserved complex stability, whereas acetonitrile caused significant destabilization. Variable-temperature ¹H/¹³C NMR confirmed stable bidentate coordination in solution. DFT calculations revealed that electron-withdrawing groups lowered LUMO energies, while electron-donating group raised HOMO levels, tuning charge-transfer behavior. ESI-MS and elemental analyses confirmed molecular purity. These results indicate that functionalization of ligands enables precise control over rhenium(I) structural and electronic properties.

Abstract Image

查看原文本刊更多论文

2,6-二（吡唑-1-基）吡啶配体羧基（COOH）、甲氧羰基（COOCH3）和氨基（NH2）功能化配合物的合成和结构表征

在365 nm的辐照下，通过在丙酮中进行Re(CO)5Br的紫外取代，合成了2,6-二（吡唑-1-基）吡啶配体与COOH、COOCH3和NH2功能化的铼(I)三羰基配合物。单晶x射线衍射显示出扭曲的八面体几何形状，ReN键长为2.133 ~ 2.239 Å， NReN角为73.30 ~ 73.98°，ReBr距离为2.627 ~ 2.642 Å，反映了配体取代基的影响。ATR-IR光谱分析表明，具有吸电子功能的COOH和COOCH3基团在ν(CO)中引起了轻微的蓝移，而NH2引起了红移，这与金属-配体背键的调制一致。紫外-可见研究表明，丙酮保持了络合物的稳定性，而乙腈引起了明显的不稳定。变温1H/13C核磁共振证实溶液中稳定的双齿配位。DFT计算表明，吸电子基团降低了LUMO能量，而给电子基团提高了HOMO能级，调整了电荷转移行为。ESI-MS和元素分析证实了分子纯度。这些结果表明，配体的功能化可以精确控制铼(I)的结构和电子性质。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Polyhedron 化学-晶体学

CiteScore

4.90

自引率

7.70%

发文量

515

审稿时长

2 months

期刊介绍： Polyhedron publishes original, fundamental, experimental and theoretical work of the highest quality in all the major areas of inorganic chemistry. This includes synthetic chemistry, coordination chemistry, organometallic chemistry, bioinorganic chemistry, and solid-state and materials chemistry. Papers should be significant pieces of work, and all new compounds must be appropriately characterized. The inclusion of single-crystal X-ray structural data is strongly encouraged, but papers reporting only the X-ray structure determination of a single compound will usually not be considered. Papers on solid-state or materials chemistry will be expected to have a significant molecular chemistry component (such as the synthesis and characterization of the molecular precursors and/or a systematic study of the use of different precursors or reaction conditions) or demonstrate a cutting-edge application (for example inorganic materials for energy applications). Papers dealing only with stability constants are not considered.