Robustness of a thioamide {⋯H–N–CS}₂ synthon: synthesis and the effect of substituents on the formation of layered to cage-like supramolecular networks in coumarin–thiosemicarbazone hybrids

Abstract

The applications of thioureas in crystal engineering have increased dramatically over the past few years. However, their analogs namely N-imino thioureas/thiosemicarbazones are largely ignored, despite the fact that these can be more interesting with respect to crystal engineering applications due to the presence of an additional N-imino moiety. Aiming to highlight their importance in crystal engineering/ supramolecular chemistry, three structurally related coumarin-thiosemicarbazone hybrids (3a-3c) have been designed, synthesized and crystallographically characterized. All of the compounds showed a general preference for the adoption of the cis, trans conformation around the central thiourea moiety; a conformation which is ideal for the formation of a dimeric hydrogen-bonded R 2 2 (8){Á Á ÁH-N-CQS} 2 synthon as the building block. Therefore, this dimeric synthon is observed in all of the compounds, regardless of the formation of layered to cage-like three dimensional supramolecular networks depending on different substituents. The prevalence of the cis, trans conformation and the robustness of the thioamide dimer synthon in thiosemicarbazones indicate its potential use as a design element in crystal engineering.

Receptor‐Spacer‐Fluorophore Based Coumarin‐Thiosemicarbazones as Anion Chemosensors with “Turn on” Response: Spectroscopic and Computational (DFT) Studies

“…The thiosemicarbazide part was prepared by reacting corresponding isothiocyanates with hydrazine in alcoholic medium, to afford respective thiosemicarbazides III . After successful synthesis of both coumarin aldehyde IV and thiosemicarbazide III , they were reacted together in ethanol to get the desired coumarin based thiosemicarbazones (R‐01‐08) ,…”

“…The synthesis of receptors ( R‐01‐08 ) were carried out in three steps following our previously reported protocol, (Scheme ) (see Supporting Information).…”

Synthesis, XRD, spectral (IR, UV–Vis, NMR) characterization and quantum chemical exploration of benzoimidazole‐based hydrazones: A synergistic experimental‐computational analysis

“…In the solid state packing, the amide moiety in both benzoimidazole‐based hydrazones 5a and 5b adopt cis‐conformation, providing the possibility of appearance of a centrosymmetric amide dimer {···H–N–C=O} 2 synthon. However, this dimeric synthon appeared in only compound 5a [(N(3)‐H(3)···O(1) 2.088 Å], facilitated by centrosymmetric CH···O interactions [(C(17)‐H(17C)···O(1) 2.353 Å] (Figure a) .…”

Tổng hợp, xác định cấu trúc và thăm dò khả năng gây độc tế bào của các phức Cu(II), Zn(II) và Ni(II) chứa 4-dimethylaminobenzaldehyde-N(4) -morpholinylthiosemicarbazone

“…Hệ liên hợp >C=N-NH-C(=S)-trong cấu trúc phân tử có khả năng ngăn chặn quá trình phiên mã, dịch mã xảy ra trong tế bào. [2] - [5].…”

“…Nhiều nghiên cứu cho rằng các dẫn xuất thế N(4)-thiosemicarbozone chứa nhóm thế dị vòng có hoạt tính tốt hơn N(4)-thiosemicarbazone chứa nhân thơm hoặc N(4)-thiosemicarbazone không nhóm thế [2] - [6]. Năm 2015, Bacher và đồng nghiệp đã công bố rằng N(4)-morpholinylthiosemicarbazone tan tốt trong dịch nội bào hơn các loại hợp chất TSC khác [7], do đó, phức chất ion kim loại chuyển tiếp chứa phối tử này được nghiên cứu tổng hợp nhằm nâng cao hiệu quả hoạt động sinh học.…”