Environmental damage and the resulting global warming are two of the most serious threats to living species. These problems are the result of industrialization in all fields. The textile and fashion industries bear a negative impact on the environment and contribute significantly to water, air, and solid waste pollution. Over the last decades, consumer buying habits have shifted, and clothing purchases have increased dramatically. The manufacturing process of these textiles, from pretreatment to dyeing and finishing, involves the use of numerous chemicals that are harmful to both humans and the planet. Textiles have been identified as unsustainable products due to their entire life cycle, from raw material cultivation to manufacturing, and generate a large amount of toxic waste and greenhouse gases. Therefore, embedding sustainability in strategy is essential to meet evolving investor pressure, consumer demand, and regulatory requirements. More alternatives are available, such as ecofriendly textiles. Governments are promoting the idea of ecolabels and sustainability standards that endorse the textile’s “ecofriendliness”. Ecolabeling stimulates consumers and manufacturers to buy and produce ecotextiles, simultaneously allowing consumers to compare the various products. Consumers are gradually requesting more ecofriendly products. To save our environment and future generations, the textile industry must become more sustainable. Major brands should implement sustainable manufacturing practices. This review paper investigates the requirements of ecofriendly textiles, restricted substances, and ecolabeling in the textile industry and highlights the need to enhance the expertise and information existing in the design process with regard to the sustainability of finished products in order to create a more sustainable textile sector. Such a shift is only feasible if the designers are guided by a clear vision of design for sustainability.

The agriculture and agri-food sectors produce substantial amounts of plant-based waste. This waste presents an identifiable research opportunity to develop methods for effectively eliminating and managing it in order to promote zero-waste and circular economies. Plant-based waste and by-products are acknowledged as valuable sources of bioactive compounds, including cellulose fibers. Direct application of these fibers in non-food sectors such as textiles can reduce the environmental impact of secondary raw materials. This review aims to provide an overview of novel concepts and modern technologies for efficiently utilizing plant-based waste and by-products from the agricultural and agro-industrial sectors to extract fibers for a variety of final applications, including the fashion industry. Two major routes are identified to produce cellulose fibers: the extraction and purification of natural cellulose fibers and the extraction and purification of cellulose pulp that is further processed into manmade cellulosic fibers. Scalability of experimental results at the laboratory or pilot level is a major barrier, so it is critical to develop closed-loop processes, apply standardization protocols, and conduct life cycle assessments and techno-economic analyses to facilitate large-scale implementation.

Organometallic complexes of the formula [Ru(N^N)(p-cymene)Cl][X] (N^N = bidentate polypyridyl ligands, p-cymene = 1-methyl-4-(1-methylethyl)-benzene, X = counter anion), are currently studied as possible candidates for the potential treatment of cancer. Searching for new organometallic compounds with good to moderate cytotoxic activities, a series of mononuclear water-soluble ruthenium(II)–arene complexes incorporating substituted pyridine–quinoline ligands, with pending -CH₂OH, -CO₂H and -CO₂Me groups in the 4-position of quinoline ring, were synthesized, for the first time, to study their possible effect to modulate the activity of the ruthenium p-cymene complexes. These include the [Ru(η⁶-p-cymene)(pqhyme)Cl][X] (X = Cl⁻ (1-Cl), PF₆⁻ (1-PF₆), pqhyme = 4-hydroxymethyl-2-(pyridin-2-yl)quinoline), [Ru(η⁶-p-cymene)(pqca)Cl][Cl] ((2-Cl), pqca = 4-carboxy-2-(pyridin-2-yl)quinoline), and [Ru(η⁶-p-cymene)(pqcame)Cl][X] (X = Cl⁻ (3-Cl), PF₆⁻ (3-PF₆), pqcame = 4-carboxymethyl-2-(pyridin-2-yl)quinoline) complexes, respectively. Identification of the complexes was based on multinuclear NMR and ATR-IR spectroscopic methods, elemental analysis, conductivity measurements, UV–Vis spectroscopic, and ESI-HRMS techniques. The solid-state structures of 1-PF₆ and 3-PF₆ have been elucidated by single-crystal X-ray diffraction revealing a three-legged piano stool geometry. This is the first time that the in vitro cytotoxic activities of these complexes are studied. These were conducted in HEK293T (human embryonic kidney cells) and HeLa cells (cervical cancer cells) via the MTT assay. The results show poor in vitro anticancer activities for the HeLa cancer cell lines and 3-Cl proved to be the most potent (IC₅₀ > 80 μΜ). In both cell lines, the cytotoxicity of the ligand precursor pqhyme is significantly higher than that of cisplatin.

Organometallic ruthenium complexes with p-cymene = 1-methyl-4-(1-methylethyl)-benzene and N^N = bidentate polypyridyl ligands constitute interesting candidates with biological and catalytic properties. Towards this aim, we have synthesized four ruthenium(II)–arene complexes of the type [Ru(η⁶-p-cymene)(N^N)Cl][X] (N^N = Br-Qpy = 6-bromo-4-phenyl-2-pyridin-2-yl-quinoline, X = Cl⁻ (1a); PF₆⁻ (1b); N^N = OH-Ph-Qpy = 4-(4-phenyl-2-(pyridin-2-yl)quinolin-6-yl)phenol, X = Cl⁻ (2a); PF₆⁻ (2b)). This is the first report of ruthenium(II) p-cymene complexes incorporating substituted pyridine–quinoline ligands, with –Br and –C₆H₄OH groups in the 6-position of quinoline. We also refer to the cytotoxicity of the ligands and their possible effect of modulating the activity of the ruthenium(II) complexes. These were characterized by a combination of spectroscopic methods (ATR-IR, UV–Vis, multinuclear NMR), elemental analysis, and conductivity measurements. The solid-state structure of 2b, determined by single-crystal X-ray diffraction, reveals a three-legged piano-stool geometry. The in vitro cytotoxic activities of the new complexes were evaluated in HEK293T (human embryonic kidney cells) and in HeLa cells (cervical cancer cells), via the MTT assay. Poor in vitro anticancer activities were observed for the HeLa cancer cell line, with 2a being the most potent (IC₅₀ = 75 μΜ). The cytotoxicity of Br-Qpy in HEK293T is comparable to that of cisplatin. Both complexes 1a and 1b successfully catalyze the transfer hydrogenation of benzophenone to benzhydrol by 2-propanol at 82 °C. The catalytic performance of 1a in the ratio of S:Cat:B = 400:1:40 (S = substrate, Cat = catalyst, B = base = KOiPr) leads to a conversion of 94%, within 3 h of reaction. Presumably, catalytic transformation takes place via ruthenium(II) hydride species being the active catalyst.

Searching for new and efficient transfer hydrogenation catalysts, a series of new organometallic ruthenium(II)-arene complexes of the formulae [Ru(η⁶-p-cymene)(L)Cl][PF₆] (1–8) and [Ru(η⁶-p-cymene)(L)Cl][Ru(η⁶-p-cymene)Cl₃] (9–11) were synthesized and fully characterized. These were prepared from the reaction of pyridine–quinoline and biquinoline-based ligands (L) with [Ru(η⁶-p-cymene)(μ-Cl)Cl]₂, in 1:2 and 1:1, metal (M) to ligand (L) molar ratios. Characterization includes a combination of spectroscopic methods (FT-IR, UV-Vis, multi nuclear NMR), elemental analysis and single-crystal X-ray crystallography. The pyridine–quinoline organic entities encountered, were prepared in high yield either via the thermal decarboxylation of the carboxylic acid congeners, namely 2,2′-pyridyl-quinoline-4-carboxylic acid (pqca), 8-methyl-2,2′-pyridyl-quinoline-4-carboxylic acid (8-Mepqca), 6′-methyl-2,2′-pyridyl-quinoline-4-carboxylic acid (6′-Mepqca) and 8,6′-dimethyl-2,2′-pyridyl-quinoline-4-carboxylic acid (8,6′-Me₂pqca), affording the desired ligands pq, 8-Mepq, 6′-Mepq and 8,6′-Me₂pq, or by the classical Friedländer condensation, to yield 4,6′-dimethyl-2,2′-pyridyl-quinoline (4,6′-Me₂pq) and 4-methyl-2,2′-pyridyl-quinoline (4-Mepq), respectively. The solid-state structures of complexes 1–4, 6, 8 and 9 were determined showing a distorted octahedral coordination geometry. The unit cell of 3 contains two independent molecules (Ru-3), (Ru′-3) in a 1:1 ratio, due to a slight rotation of the arene ring. All complexes catalyze the transfer hydrogenation of acetophenone, using 2-propanol as a hydrogen donor in the presence of KOiPr. Among them, complexes 1 and 5 bearing methyl groups at the 8 and 4 position of the quinoline moiety, convert acetophenone to 1-phenylethanol quantitatively, within approximately 10 min with final TOFs of 1600 h⁻¹. The catalytic performance of complexes 1–11, towards the transfer hydrogenation of p-substituted acetophenone derivatives and benzophenone, ranges from moderate to excellent. An inner-sphere mechanism has been suggested based on the detection of ruthenium(II) hydride species.

Herein, a series of ruthenium(II) bis‐triphenylphosphine complexes comprising substituted pyridine–quinoline based ligands for the efficient α‐alkylation of ketones with primary alcohols, via the borrowing hydrogen methodology, are reported. β‐alkylation of secondary alcohols by primary alcohols is also reported. The reactions are catalyzed by the ruthenium complexes [RuCl₂(8‐Mepq)(PPh₃)] (1), [RuCl₂(6′‐Mepq)(PPh₃)₂] (2), [RuCl₂(4,6′‐Me₂pq)(PPh₃)₂)] (3), including [RuCl₂(4‐Mepq)(PPh₃)₂] (4), and [RuCl₂(pq)(PPh₃)₂] (5). Mass spectrometry, elemental analysis, and ³¹P NMR data reveal that 1 is a five‐coordinate 16‐electron ruthenium(II) complex with one triphenylphosphine ligand, as opposed to 2–5, which hold two and are six‐coordinate. Theoretical calculations suggest that 1 is stabilized by a nonclassical RuCl(1)···H(2) interaction between a hydrogen atom of the appended methyl group and an adjacent chlorine atom. By NMR spectroscopy, different isomers of 2 and 3 have been detected. For the α‐alkylation of benzyl alcohol with acetophenone, all complexes selectively provided 1,3‐diphenylpropan‐1‐one as the sole product, within an hour. The β‐alkylation of 1‐phenylethanol with benzyl alcohol under the same conditions is less selective. As salient features of this report we could mention that these catalytic systems operate with easily accessible and in high yields air‐stable catalysts, within a shorter period compared to known ruthenium complexes.