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Theoretical explanation for catalytic hydrosilylation of some organic molecules mediated by a phosphorus dication compound
(Eskişehir Teknik Üniversitesi, 2021) Yıldız, Cem Burak
Catalysis reactions under metal-free and ambient conditions have received great interest in terms of economic and environmental issues. Especially, the applications of Lewis acids for the processes are having special interest due to their unique roles in a huge number of organic reactions. In this sense, a recent compound PIII dication has played an important role in the catalytic hydrosilylation of carbonyls and olefins. Herein theoretical calculations were carried out to elucidate the mechanisms of the experimentally reported and unknown reactions. The proposed mechanisms show that the reactions of a-d can occur spontaneously, whereas the formation of pyridine has an endergonic nature.
Farklı demir (Fe) formu uygulamalarının ekmeklik ve makarnalık buğday çeşitlerinin tane Fe konsantrasyonuna etkisi
(Harran Üniversitesi Ziraat Fakültesi, 2021) Uysal, Selçuk; Erdem, Halil; Gence, Cabir Çağrı
Bu çalışmada, sera koşullarında ekmeklik ve makarnalık buğday çeşitlerine farklı Fe form (FeSO4.7H2O; Fe-EDTA; Fe-EDDHA) ve uygulama şekillerinin (toprak, yaprak ve toprak+yaprak) tane Fe konsantrasyonuna olan etkisi araştırılmıştır. Elde edilen sonuçlara göre; topraktan (0 ve 5 mg Fe kg-1), yapraktan (%0.2 Fe) , toprak + yapraktan (0 ve 5 mg Fe kg-1 toprak + %0.2 Fe yaprak) farklı Fe formu (özellikle Fe-EDTA ve FeSO4) uygulamalarının ekmeklik ve makarnalık buğday çeşitlerinin kuru madde verimi, tane verimi ve 1000 tane ağırlıkları ile tane Fe konsantrasyonlarında istatiksel (p<0.05) olarak önemli düzeyde artışlara neden olduğu tespit edilmiştir. Ekmeklik buğday çeşidinin kontrol uygulamasında tane Fe konsantrasyonu 29.2 mg kg-1 iken, toprak+yapraktan Fe uygulamasıyla tane Fe konsantrasyonu sıra ile FeSO4 formunda 44.3 mg kg-1 (%51.7 artış), Fe-EDTA formunda 43.7 mg kg-1 (%53.4 artış), Fe-EDDHA formunda ise 44.8 mg kg-1’a (%49.6 artış) çıkmıştır. Uygulama şekilleri bakımından tane Fe konsantrasyonları değerlendirildiğinde, toprak+yaprak uygulamasının diğer uygulamalara (toprak, yaprak) göre ekmeklik ve makarnalık buğday çeşitlerinin tane Fe konsantrasyonlarında daha fazla artışa neden olduğu görülmüştür. Sonuç olarak FeSO4 ve Fe-EDTA formlarının toprak+yaprak uygulamaları ile ekmeklik ve makarnalık buğday çeşitlerinin hem verim parametreleri hem de tane Fe konsantrasyonlarında önemli düzeyde artışa neden olduğu ortaya çıkmıştır.
Tuzlu toprakların hidrokimyasal parametrelerinin laboratuvar koşullarında belirlenmesi
(Ondokuz Mayıs Üniv. Ziraat Fakültesi, 2020) Dursun, Seyit Ali; Mikailsoy, Fariz
Bu çalışma, yıllık yağışın az, aşırı buharlaşmanın ve taban suyunun yüzeye yakın olması nedeniyle oluşan tuzluluğun, bitkinin gelişmesine, verime ve toprağın çoraklaşmasına olumsuz etkisinin yıkamayla ortadan kaldırılması amacıyla yapılmıştır. Tuzlu toprakların ıslahı, maliyetli ve zaman gerektiren bir süreçtir. Çözünebilir tuzların yıkanması amacıyla kullanılan matematiksel yöntemler, toprakların ıslahında su-tuz rejiminin modellenmesinde doğrudan ve ters problemlerin çözümü için yaygın olarak kullanılmaktadır. Tuz taşınım modelinin uygulanabilirliği, modelin süreçlerini tanımlayan hidrodinamiklerin diferansiyel eşitliklerinin deneysel parametrelerinin doğruluğuna bağlıdır. Laboratuvar koşullarında yapılan çalışmada 20 cm çapında kolonlar kullanılarak toprakta tuz taşınımının hidrokimyasal göstericileri olan; konvektif difüzyon ve dispersiyon (yayılma) parametreleri, toprak gözeneklerindeki su akış hızı=belirlenmiştir. Yıkama döneminde CI- ve SO4iyonları için hidrokimyasal dispersiyon parametresi (λ),değerleri sırasıyla 9.26.10-2 m ve 9.60.10-2 m; konvektif difüzyon parametresi (D) ise 4.51.10-3 m2 gün-1 ve 4.67.10-3 m2 gün-1 olarak belirlenmiştir.
Borlu toprakların ıslahı için gerekli yıkama suyunun belirlenmesine yönelik matematiksel modellerin elde edilmesi
(TENMAK Bor Araştırma Enstitüsü, 2019) Dursun, Seyit Ali; Mikailsoy, Fariz
Tuzlu toprakların ıslahında kullanılacak olan yıkama suyu miktarının belirlenmesi,yapılacak yıkamanın başarısı açısından önemlidir. Bu çalışma, Aksaray ÜniversitesiYerleşkesinde 500 ha borlu-sodyumlu alana sahip topraklarda gerçekleştirilmiştir. Boryıkama verilerini elde etmek için dokuz adet (2 x 2 m) parsel kullanılmıştır. Parsellerin0-25, 25-50, 50-75, 75-100 cm derinlikten toprak örnekleri alınmış ve elde edilendeğerlerle yıkama suyu miktarı modelleri oluşturulmuştur. Toprak pH’nın yüksek olmasısebebiyle, pH’nın düşürülmesi ve yıkama etkinliğinin arttırılması amacıyla yıkamaparsellerine 4 ve 8 kg kükürt (S) kullanılmıştır. Yıkama suyu 30 cm olarak dört periyottaverilmiştir. Elde edilen yıkama suyu miktarının ampirik modellerinin farklı matematikselifadeleri olan; hiperbol, üstel, kuvvet ve logaritmik modeller ele alınmış ve her kükürtdozu için en uygun modeller tespit edilmiştir. Bu modellerin uygunluğunun tespiti içinmodel seçim ölçütleri uygulanmıştır. Uygulamada elde edilen matematiksel modellerseçim ölçütlerine göre değerlendirildiğinde, S1 uygulamasında deneysel verileri enbaşarılı logaritmik model tanımlamaktadır.
Azot uygulamalarının ekmeklik buğday çeşitlerinin tane sterol (campesterol, stigmasterol ve betasitosterol) konsantrasyonuna etkisi
(Ordu Üniversitesi Ziraat Fakültesi, 2018) Tosun, Yener Kortan; Erdem, İbrahim Halil; Gence, Cabir Çağrı
Bitki sterolleri (fitosterol) insan sağlığı için çeşitlibiyoaktif özelliklere sahip bir grup steroid alkoldür.Fitosteroller kolesterolün bağırsaktaki emiliminiengelleyerek kandaki kolesterol seviyelerini düşürücü etkiye sahiptirler. Bu çalışmanın amacı sera koşullarında iki farklı ekmeklik buğday çeşidine (Yunus veOsmaniyem) azot (N) uygulamalarının tane Campesterol, Stigmasterol ve Betasitosterol konsantrasyonlarına olan etkisi araştırılmıştır. Çalışmada N uygulamaları topraktan 250 ve 500 mg kg-1 dozlarındayapılmış, 500 mg kg-1 N uygulamasına ayrıca üç farklı dönemde (sapa kalkma, başaklanma ve tane olum)yapraktan % 0.5 üre verilmiştir. Azot uygulaması ilehem Yunus hem de Osmaniyem çeşitlerinin tane Nkonsantrasyonlarında istatistiksel olarak önemliartışlar görülmüştür. Azot uygulaması ile Yunusçeşidinin tanesinde %89, Osmaniyem çeşidinde ise%62’lik bir N konsantrasyonu artışı meydana gelmiştir. Azot uygulaması ile tane N konsantrasyonlarında görülen artışa paralel olarak Yunus çeşidininCampesterol konsantrasyonunda %45, Stigmasterolkonsantrasyonunda %145 ve Betasitosterol konsantrasyonunda ise %105 düzeyinde bir artış olduğugörülmüştür. Osmaniyem çeşidinin Campesterolkonsantrasyonunda %99, Stigmasterol konsantrasyonunda %38, Betasitosterol konsantrasyonunda ise%73 artış meydana gelmiştir. Elde edilen sonuçlardan N’un Campesterol, Stigmasterol ve Betasitosterol yapısına katılma ihtimalinin yüksek olduğu görülmektedir.
Production of Bioethanol from Waste Potato
(Turkish Science and Technology Publishing (TURSTEP), 2015) Duruyürek, Merve; Düşgün, Cihan; Gülhan, Mehmet Fuat; Selamoğlu,Zeliha
Using primary energy sources in World as fossil fuels, causes air pollution and climate change. Because of these reasons, people looking for renewable energy suppliers which has less carbondioxide and less pollution. Carbon in biofuels is producing from photosynthesis. For this, burning biofuels don t increase carbondioxide in atmosphere. Scientists predict that plants with high carbonhydrate and protein contents are 21. centuries biofuels. Potatoes are producing over 280 million in whole world and Turkey is 6th potato producer. Turkey produces 5250000 tonne of potatoes. Approximately 20% of potatoes are waste in Niğde. Our study aimed to produce bioethanol from Solanum tuberosum by using the yeast Saccharomyces cerevisiae. As a result renewable energy sources can be produced from natural wastes.
Mitigation effect of grape seed extract against cadmium-induced hormonal toxicity in common carp (Cyprinus carpio)
(Springer Nature, 2025) Korkmaz, Nuh; Erdoğan, Kenan; Örün, Gül Nihal; Erkmen, Belda; Doğru, Mehmet ilker; Doğru, Arzu; Polat, Hüseyin; Örün, İbrahim
Background Cadmium (Cd), a highly toxic heavy metal, poses a significant threat to aquatic organisms by disrupting endocrine and metabolic processes. Its bioaccumulation in fish can impair hormonal regulation, leading to growth suppression, stress, and thyroid dysfunction. Alternative strategies using natural compounds are being explored to mitigate these toxic effects in aquaculture. Objective In this study, the protective potential of grape (Vitis vinifera L.) seed extract (GSE) against the toxic effects of cadmium (Cd) on growth hormone, stress hormones, and thyroid hormones in common carp (Cyprinus carpio L.) was investigated for the first time. Methods A total of 420 common carp (average weight: 75±5.0 g; average length: 15±2.0 cm) were used, and the experiments were conducted over acute (4 days) and subchronic (30 days) periods. The fish were randomly divided into seven groups, including a control group, a vehicle group (ethanol), a cadmium-only group (20 ppb), two groups receiving GSE alone (5 mg/kg and 10 mg/kg), and two groups receiving cadmium combined with GSE (5 mg/kg and 10 mg/kg). The GSE dosages were calculated based on the body weight of each fish (mg of extract per kg of fish body weight) and administered daily via gavage. Results Cadmium exposure caused significant hormonal disruptions in common carp, including reductions in growth hormone, insulin-like growth factor 1, thyroid-stimulating hormone, and triiodothyronine levels, along with elevations in cortisol and thyroxine levels during both acute and subchronic exposure periods (P<0.05). Grape seed extract treatment mitigated many of these effects, particularly in the acute phase. It improved growth hormone and insulin-like growth factor 1 levels, reduced elevated cortisol concentrations, and notably increased free triiodothyronine levels, thereby contributing to the partial restoration of thyroid hormone balance. However, in the subchronic period, some hormonal disruptions-especially reduced growth hormone levels-persisted despite GSE administration. Conclusions These findings suggest that GSE may serve as a natural protective agent against heavy metal toxicity (Cd) and offer an alternative solution in aquaculture.
Assessment of the levels of heavy metal pollution in roadside soils of Termiz – Taskent, Uzbekistan
(Polskie Towarzystwo Inzynierii Ekologicznej (PTIE), 2025) Kholikulov, Shodi Turdukulovich; Erdem, Halil; Bobobekov, Isomiddin Nuriddinovich; Demir, Saniye; Gence, Cabir Çağrı
This study investigates the contamination of roadside soils by heavy metals (Pb, Zn, Ni, and Mo) along the Tashkent- Termiz International M-39 highway, utilizing indices such as the enrichment factor (EF), geo-accumulation index (Igeo), and pollution load index (PLI). Soil samples collected at 21 distances (5–1000 m) indicate that metal concentrations decrease with distance from the road, with rapid reductions observed within the 5–100 m range. Pb levels decline from 24 mg kg-1 at 5 m to 1.4 mg kg-1 at 1000 m, while Zn reduces from 26.3 mg kg-1 to 2.1 mg kg-1. Ni and Mo follow similar trends, but Mo exhibits lower mobility. Pb, Zn, and Ni stand out as indicators of anthropogenic pollution, with high correlation values between their DTPA-extractable and total concentrations (R2: Pb = 0.953, Zn = 0.930, Ni = 0.932). The Igeo values reveal moderate to high contamination near the road, particularly for Pb and Zn. The EF values for Mo (2.06) suggest moderate enrichment due to anthropogenic sources, such as traffic emissions, while Pb (0.76), Zn (0.89), and Ni (0.93) show minimal enrichment. PLI values of 4.24, 4.03, 3.63, and 4.87 for Pb, Zn, Ni, and Mo, respectively, classify the area as “highly polluted” for most metals. These findings highlight the significant anthropogenic contribution to heavy metal accumulation, driven by vehicular emissions, tire wear, and industrial activities. The contamination poses risks to soil health, biodiversity, and human safety through bioaccumulation in the food chain. Sustainable environmental management and pollution mitigation strategies are urgently required to address these concerns and safeguard agricultural productivity and ecosystem functions.
Microplastics in Soil Increase Cadmium Toxicity: Implications for Plant Growth and Nutrient Imbalance
(2025) Erdem, Halil; Gence, Cabir Çağrı; Öztürk, Mehmet; Buhan, Ekrem; Kholikulov, Shodi Turdukulovich; Kaya, Yağmur
The increasing presence of microplastics (MPs) and cadmium (Cd) in agricultural soils represents an emerging environmental challenge, necessitating urgent investigation due to their potential synergistic effects on soil and plant health. This study investigated how polyethylene microplastics (PE-MPs) affect Cd behavior in soil, focusing on both their individual and combined impacts on soil pH, Cd bioavailability, plant growth, and nutrient dynamics. MPs can act as carriers of Cd, enhancing its mobility within the soil–plant system. To achieve this, a pot experiment was conducted using soils treated with different doses of PE MPs (0%, 1%, and 2%, w/w) and Cd (20 mg Cd kg−1). Soil pH, DTPA-extractable Cd, plant growth parameters, Cd accumulation in roots and shoots, and mineral nutrient concentrations were measured. The results indicated that while Cd alone did not significantly alter soil pH, increasing MP doses statistically reduced soil pH and enhanced Cd bioavailability, with DTPA-extractable Cd rising by 14.4% to 25.4%. The combined application of MPs and Cd resulted in a 38% reduction in root yield and a 32% decrease in above-ground biomass. The presence of MPs exacerbated Cd uptake, leading to significantly higher Cd accumulation in both roots and shoots compared to Cd application alone. Moreover, the combined presence of MPs and Cd disrupted the nutrient uptake mechanisms, as evidenced by significant reductions in nitrogen (N) and phosphorus (P) concentrations in root and shoot tissues. These results indicate that MPs and Cd together disrupt soil chemical stability and compromise plant nutritional status. Thus, our findings emphasize that MPs not only serve as physical pollutants but also as vectors that intensify heavy metal contamination risks in agricultural ecosystems.
Potential protective effect of hesperidin (Vitamin P) against hlyphosate-induced spermatogenesis damage in male rats: biochemical and histopathological findings on reproductive parameters
(MDPI, 2024) Güngör, Şükrü; Kırıkkulak, Murat; Denk, Barış; Gülhan, Mehmet Fuat; Güleş, Özay; Budak, Duygu; İnanç, Muhammed Enes; Avdatek, Fatih; Yeni, Deniz; Taşdemir, Umut
The aim of this study was to investigate the effectiveness of hesperidin (HES) on testicular histopathological changes, biochemical changes, and semen characteristics in rats exposed to glyphosate (GLP). The control group was given a normal diet devoid of GLP and HES, the HES group was given 100 mg/kg/day HES with the normal diet, the GLP group was given GLP at the LD50/10 dose of normal feed, which was 787.85 mg/kg/day, and the GLP + HES group was given normal feed containing 787.85 mg/kg/day LD50/10 dose of GLP in addition to 100 mg/kg/day HES. GLP administration reduced sperm motility, sperm plasma membrane integrity, glutathione levels, and total antioxidant levels in the testicular tissues of rats. Moreover, it caused an increase in right testis and left epididymis weights, abnormal sperm counts, malondialdehyde levels, total oxidant status, and DNA damage. The HES treatment showed curative effects on these parameters. Furthermore, HES was effective in lessening the histopathological damage that was caused by GLP. The results showedthat HES protects spermatological parameters and DNA integrity, improves antioxidant defenses, and lowers the damage and lipid peroxidation caused by GLP in testicular tissue.
Physico-chemical and microbiological properties of water kefr produced from carob (Ceratonia siliqua L.) sherbet
(The Korean Society of Food Science and Technology, 2025) Gülhan, Mehmet Fuat; Gülhan, Ayça; Düşgün, Cihan
In this study, sugar-free (A) and sugar-added (B) formulations of carob sherbet were fermented with water kefir grains. After 48 h of fermentation, the pH and total soluble solid content level (TSS) of A and B decreased, while the titratable acidity (TA) value increased. At the end of fermentation, Ave B formulations were stored at 4 °C for 28 days. Fermented sherbets’ 2,2?-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity decreased with storage. A had 75.3% DPPH radical scavenging activity on day 0th, whereas B had 77.0%. B had less total phenolic content (TPC) than fermented A on day 0. TPC values decreased significantly, notably on days 21st and 28th of storage. After fermentation, A had more gallic acid, hesperidin, p-coumaric acid, rosmarinic acid, and syringic acid than B. A had 2.21% sucrose before fermentation and 0.95% after. On 14th days of storage, potassium and calcium had the greatest mineral levels. Compared to A, B gave higher microbial count values (Lactobacillus sp., Lactococcus sp. total mesophilic aerobic bacteria, and yeast) in the microbiological analysis results at the end of fermentation and during storage.
Effect of biochars produced at different pyrolysis temperatures on Ammonium (NH4+) and Nitrate (NO3-) Leaching: Column experiment
(Hasan ÖNDER, 2024) Gence, Cabir Çağrı; Erdem, Halil
Nitrogen (N) leaching from agricultural soils is a global problem with negative effects on both human health and the environment. Efforts should be made to increase the efficiency of use of plant nutrients and minimize N losses from terrestrial ecosystems to aquatic ecosystems. In this study, the effects of different doses (%0, %1 and %2) of biochar obtained from corn cob and rice husk biomass, which are agricultural production residues, at three different temperatures, on ammonium (NH4+) and nitrate (NO3-) leaching in a coarse-textured soil were investigated. Polyethylene (PE) columns with a diameter of 70 mm and a height of 20 cm were used in the study, which was carried out in three replications according to the randomized plots experimental design. Total nitrogen (27 kg N da-1) and water amounts (969 mm) used for 6 tons da-1 yield of sugar beet were applied. Total water was given to each column in equal volume using drip adjustment sets at one-week intervals, simulating 6 irrigation periods, and the leaked water was collected in each irrigation period and NO3- and NH4+ concentrations were determined. Applications of 1 and 2 doses of corn and rice biochars obtained at three different pyrolysis temperatures caused a significant decrease in NH4+ concentrations leaching from the column. Similarly, biochar applications (especially 2% dose) caused a significant decrease in NO3- concentrations leaching from the column. While the total NO3- concentration leaching from the control columns was 149.23 mg kg-1, 2% dose of rice husk biochars at 300, 400 and 500 ? temperature applications caused a decrease in the total NO3- concentrations washed from the column by 51%, 55% and 51%, respectively. The results revealed that biochar applications significantly reduced nitrogen leaching from the soil.
Structural dynamics and anti-biofilm screening of novel imidazole derivative to explore their anti-biofilm inhibition mechanism against Pseudomonas Aeruginosa
(Taylor and Francis Ltd., 2024) Mehmood, Shahab; Hussain, Mumtaz; Bux, Khair; Hussain, Zahid; Raza Shah, Muhammad; Ali Jakhrani, Mushtaque; Ali Channar, Pervaiz; Begum, Irshad; Saboor, Rukhsana; Yıldız, Cem B.; Ali, Kashif; Herwig, Ralf
The biofilm formation is still prevalent mechanism of developing the drug resistance in the Pseudomonas aeruginosa, gram-negative bacteria, known for its major role in nosocomial, ventilator-associated pneumonia (VAP), lung infections and catheter-associated urinary tract infections. As best of our knowledge, current study first time reports the most potent inhibitors of LasR, a transcriptional activator of biofilm and virulence regulating genes in, Pseudomonas aeruginosa LasR, utilizing newly functionalized imidazoles (5a-d), synthesized via 1,3-dipolar cycloaddition using click approach. The synthesized ligands were characterized through Mass Spectrometry and 1H NMR. The binding potency and mode of biding of ligands. Quantum Mechanical(QM) methods were utilized to investigate the electronic basis, HOMO/LUMO and dipole moment of the geometry of the ligands for their binding potency. Dynamics cross correlation matrix (DCCMs) and protein surface analysis were further utilized to explore the structural dynamics of the protein. Free energy of binding of ligands and protein were further estimated using Molecular Mechanical Energies with the Poisson–Boltzmann surface area (MMPBSA) method. Molecular Docking studies revealed significant negative binding energies (5a ? 10.33, 5b ?10.09, 5c ? 10.11, and 5d ?8.33 KJ/mol). HOMO/LUMO and potential energy surface map estimation showed the ligands(5a) with lower energy gaps and larger dipole moments had relatively larger binding potency. The significant change in the structural dynamics of LasR protein due to complex formation with newlyfunctionalized imidazoles ligands.
Cryopreservation of ram semen: baicalein efficiency on oxidative stress, chromatin integrity, viability and motility post thaw
(Frontiers Media SA, 2024) Avdatek, Fatih; Güngör, Şükrü; Gülhan, Mehmet Fuat; İnanç, Muhammed Enes; Olğaç, Kemal Tuna; Denk, Barış; Yeni, Deniz; Taşdemir, Umut
Baicalein (B) has potential antioxidant properties, but it has not been tested as a ram semen extender. This study aimed to assess the impact of B on various sperm parameters and determine its potential influence on semen quality after the freeze-thawing process. During the breeding season, ejaculates were obtained from four rams with the aid of an artificial vagina. The collected mixed semen samples were divided into four groups: control (C; 0), B0.5 (0.5 mM), B1 (1 mM), and B2 (2 mM). After semen extension, the samples were loaded into 0.25 mL straws and stored for 2 h at 4°C prior to freezing in liquid nitrogen vapor and thawed in a water bath at 37°C. Among the groups, B0.5 demonstrated the highest progressive motility results, while B1 and B2 exhibited reduced motility (p < 0.05). In terms of high mitochondrial membrane potential, plasma membrane and acrosome integrity, and viability, B0.5 showed significantly superior outcomes to the other B groups (p < 0.05), although it was not significantly better than C. B1 displayed the highest plasma membrane integrity levels (p < 0.05). Notably, B2 displayed the lowest total antioxidant status levels among the groups (p < 0.05). The findings of this study suggested that the in vitro spermatological characteristics of ram spermatozoa such as progressive motility and chromatin integrity can be protected from the freeze-thawing process by using the 0.5 mM dose of baicalein as a semen extender. The treatment of sperm freezing might benefit from further in-depth research on the role of B in the improvement of cryoinjury and its underlying processes.
Dianionic and Neutral Diboron-Centered Classical Diradicaloids
(American Chemical Society, 2024) Elvers, Benedict J.; Das, Ayan; Chrysochos, Nicolas; Uddin, Sk Imraj; Gangber, Tejaswinee; Gangber, Tejaswinee
Herein, we report the syntheses and electronic structures of crystalline dianionic as well as neutral diboron-centered classical diradicaloids as boron analogues of classical Thiele, Chichibabin, and Müller (this only for dianionic diradicaloids!) hydrocarbons. These are based on borane radical anion and NHC-stabilized boryl radical spin carriers, respectively. All these dianionic diboron-centered diradicaloids exhibit triplet population at room temperature regardless of the ?-conjugated spacer: p-phenylene, p,p?-biphenylene, or p,p?-terphenylene. In the case of neutral diboron-centered diradicaloids, the employed ?-conjugated spacer plays a crucial role for the triplet population at room temperature: EPR inactive for p-phenylene vs EPR active for p,p?-biphenylene. The findings emphasize the importance of the spin carriers for the resulting ground-state: borane radical anion vs NHC-stabilized boryl radical along with the pivotal role of the ?-conjugated spacer as spin-coupler between two spins. Notably, 100 years (a century) after the first report by Krause of the triphenyl borane radical-anion, being isoelectronic to the triphenylmethyl radical, we convey borane radical anion-based diradicaloids. Furthermore, while donor-stabilized boryl radicals were introduced in the 1980s by Giles and Roberts, said concept is herewith being extended to NHC-stabilized boryl radical-based diradicaloids.
Comment on "Disclosing Cyclic(Alkyl)(Amino)Carbenes as a One-Electron Reductant: Synthesis of Acyclic(Amino)(Aryl)Carbene-Based Kekulé Diradicaloids"
(Wiley-VCH - Home, 2023) Maiti, Avijit; Elvers, Benedict J.; Bera, Sachinath; Lindl, Felix; Krummenacher, Ivo; Ghosh, Prasanta; Braunschweig, Holger; Yıldız, Cem B.; Schulzke, Carola
The authors would like to correct a misassignment of an EPR spectrum in the title paper (https://doi.org/10.1002/chem. 202104567). The authors of the original paper reported the one-electron oxidation of the cyclic(alkyl)(amino)carbene (CAAC) 1 to produce the intermediate iminium radical cation 2, as deduced from the high isolated yield of the hydrogen abstraction product 3 (Figure 1). By low-temperature (200 K) EPR spectroscopy, we observed a weak transient, three-line EPR spectrum with a g-factor of 2.0043 and a 14N hyperfine splitting (hfs) of a( 14N)=5.9 G, which we attributed to the radical cation 2 (the spectrum was depicted as Figure 1b, in the TOC cover image, in the Cover Feature (https://doi.org/10.1002/chem. 202201219), and as Figure S46 of the original paper). However, as one of the present authors (H.G.K.) later pointed out, the foregoing EPR parameters, in particular the g-factor, would not be in agreement with the proposed vinyl-type ?-radical cation.
Intramolecular donor-stabilized tetra-coordinated germanium(iv) di-cations and their Lewis acidic properties
(Royal Society of Chemistry, 2023) Yıldız, Cem Burak; Khan, Souvik; Gonnade, Rajesh G.; Majumdar, Moumita
We report the first examples of intramolecular phosphine-stabilized tetra-coordinated germanium(iv) di-cationic compounds: [LiPr2Ge][CF3SO3]23iPr and [LPh2Ge][CF3SO3]23Ph (LiPr = 6-(diisopropylphosphanyl)-1,2-dihydroacenaphthylene-5-ide; LPh = 6-(diphenylphosphanyl)-1,2-dihydroacenaphthylene-5-ide). The step wise synthetic strategy involves the isolation of neutral and mono-cationic Ge(iv) precursors: [LiPr2GeCl][X] (X = GeCl31iPr, OTf 2iPr), [LPh2GeCl2] 1Ph and [LPh2GeCl][OTf] 2Ph. Both 3iPr and 3Ph exhibit constrained spiro-geometry. DFT studies reveal the dispersion of di-cationic charges over P-Ge-P sites. Anion or Lewis base binding occurs at the Ge site resulting in relaxed distorted trigonal bipyramidal/tetrahedral geometry. 3iPr and 3Ph activate the Si-H bond initially at the P-site. The hydride ultimately migrates to the Ge-site rapidly giving [LPh2GeH][CF3SO3] 3PhH, while sluggishly forming [LiPr2GeH][CF3SO3] 3iPrH. Compounds 3iPr and 3Ph were tested as catalysts for the hydrosilylation of aromatic aldehydes. While catalytic hydrosilylation proceeded via the initial Et3Si-H bond activation in the case of 3iPr, compound 3Ph as a catalyst showed a masked Frustrated Lewis Pair (FLP) type reactivity in the catalytic cycle.
Effects of Nitrogen and Zinc Fertilization on Alleviating Cadmium Accumulation in Durum Wheat Grains
(Taylor and Francis Ltd., 2023) Tosun, Yener Kortan; Erdem, Halil; Gence, Cabir Çağrı
Cadmium (Cd) accumulation in durum wheat (Triticum durum L.) is of particular concern compared to the other commonly cultivated cereals. This study was conducted to determine the effects of zinc (Zn) and nitrogen (N) applications on grain Cd concentration of durum wheat grown in a Cd contaminated soil. The experimental design consisted of randomized plots with four replications. The treatments included low and adequate (0.05 and 5 mg kg?1) Zn doses, and inadequate, optimal and high (200, 400 and 600 mg kg?1) N doses. Cadmium application rates were 0 and 5 mg kg?1. The findings demonstrated that Cd application caused a significant increase in grain Cd concentrations, and a decrease in straw and grain yields under low and adequate doses of Zn and all N doses. However, increasing N applications with adequate soil Zn caused an increase in the straw and grain yields and a significant decrease in grain Cd concentration. The grain Cd concentration in low Zn and optimum N treatment under Cd application was 6206 µg kg?1, while the grain Cd concentration decreased by 26.3% (4574 µg kg?1) in the Zn and optimum N treatment. In addition, the grain Zn concentration of durum wheat under low soil Zn conditions was decreased in Cd application, whereas the grain Zn concentration increased in Cd application under adequate soil Zn concentration. The results revealed that combined application of N and Zn in Zn deficient soils is highly effective at decreasing Cd accumulation in wheat grains compared to individual applications.
A Zwitterionic Tetrastanna(II) Cyclic Crown
(John Wiley and Sons Inc, 2023) Sahoo, Padmini; Chibde, Purva; Das, Satyabrata; Banerjee, Subhrashis; Vanka, Kumar; Gonnade, Rajesh G.; Yıldız, Cem. B.; Majumdar, Moumita
A 12-membered zwitterionic tetrastanna(II) cycle 1 having a crown ether-like topology has been isolated from the deprotonation of 1,1?-methylenediimidazole (B) with two equivalents of Sn[N(SiMe3)2]2 (A). The solid-state structure and NMR analysis confirms the tetrastanna(II) cycle 1 to be comprised of two stannate(II) and two stannyliumylidene ion pairs in alternating positions of the heterocycle. Computational analysis shows greater nucleophilicity at the proximally located stannate(II) centers. Nonetheless, the tetrastanna(II) cycle 1 remains poorly reactive due to engagement of SnII lone pair electrons in intramolecular donor-acceptor interactions. Simple deprotonation reaction between Sn[N(SiMe3)2]2 (A) and N-(diisopropylphenyl)imidazole (C) in equimolar ratio has led to a stannylene 2, involving the formation of a Sn?C covalent bond with the anionic imidazol-2-yl carbon center along with the release of NH(SiMe3)2. Compound 2 exists as a dimer, where the unsubstituted ring nitrogen atom coordinated intermolecularly to the other stannylene center.
Reduction of 2-H-substituted pyrrolinium cations: the carbon-carbon single bond in air stable 2,2?-bipyrrolidines as a two-electron-source
(Royal Society of Chemistry, 2023) Nayak, Mithilesh Kumar; Elvers, Benedict J.; Mandal, Debdeep; Das, Ayan; Ramakrishnan, Raghunathan; Mote, Kaustubh R.; Schulzke, Carola; Yıldız, Cem Burak; Jana, Anukul
Reduction of 2-H-substituted pyrrolinium cations via initially formed secondary radicals results in either dimerisation or H-abstracted products, while the outcome depends on the N-substituents. The resultant central carbon-carbon single bond in the dimerised 2,2?-bipyrrolidine derivatives can be oxidised chemically and electrochemically. The notably air and moisture-stable dimers were subsequently utilised as a source of two electrons in various chemical transformations.

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