Molecular Structures Of Complexes Research Articles

Regioselective Rhodium‐Catalyzed 1,2‐Hydroboration of Pyridines and Quinolines Enabled by the Tris(8‐quinolinyl)phosphite Ligand**

AbstractA Rh(I) complex [κ2(P,N)‐{P(Oquin)3}RhCl(PPh3)] (1) bearing the P,N ligand tris(8‐quinolinyl)phosphite, P(Oquin)3, has been synthesized and structurally characterized. The molecular structure of complex 1 shows that P(Oquin)3 acts as a bidentate P,N chelate ligand. Reactivity studies of 1 reveal that the triphenylphosphine ligand can be replaced by Pcy3 or removed upon oxidation with concomitant coordination of a second 8‐quinolyl unit of P(Oquin)3. In addition, the Rh(III) complex [RhCl2{OP(Oquin)2}] (3), resulting from treating 1 with either wet CDCl3 or, sequentially, with HCl and water, was identified by X‐ray diffraction analysis. Complex 1 catalyzes the 1,2‐regioselective hydroboration of pyridines and quinolines, affording N‐boryl‐1,2‐dihydropyridines (1,2‐BDHP) and N‐boryl‐1,2‐hydroquinolines (1,2‐BDHQ) in high yield (up to >95 %) with turnover numbers (TONs) of up to 130. The system tolerates a variety of substrates of different electronic and steric nature. In comparison with other transition‐metal‐based hydroboration catalysts, this system is efficient at a low catalyst loading without the requirement of base or other additives.

The Molecular Diversity Scope of Meldrum's Acid in Multicomponent Reactions

AbstractMulticomponent reactions (MCRs) have gained significant attention in the field of organic synthesis due to their ability to efficiently construct complex molecular structures in a single step. Among the reagents employed in MCRs, Meldrum's acid has emerged as a highly versatile and valuable starting material, offering a wide range of molecular diversity. This comprehensive review explores the molecular diversity scope of Meldrum's acid in various MCRs, focusing on its unique attributes and the greener aspects of its application. Meldrum's acid possesses several remarkable features that contribute to its suitability as a key component in MCRs. Its high acidity enables effective participation in a variety of chemical reactions, while its rigid structure provides stability and allows for precise control of the reaction pathways. Furthermore, the ability of Meldrum's acid to undergo both nucleophilic and electrophilic attacks makes it highly versatile in the construction of diverse molecular frameworks. Its low steric hindrance further enhances its reactivity, facilitating efficient bond formation. By surveying the literature from the last five years (2018–2022), we delve into the broad range of applications of Meldrum's acid in MCRs. The review encompasses the synthesis of various heterocyclic compounds, highlighting the significance of Meldrum's acid in achieving molecular diversity. Moreover, particular emphasis is placed on the greener aspects of utilizing Meldrum's acid, considering the growing demand for environmentally friendly synthetic approaches. This includes exploring greener solvents, milder reaction conditions, and reduced waste generation.

Emulsification properties of sugar beet pectin: The synergistic effect of homogalacturonan and rhamnogalacturonan-Ⅰ

In recent years, sugar beet pectin has been shown to exhibit excellent emulsifying properties compared to commercial citrus peel pectin and apple pectin, with emulsifying properties similar to those of gum arabic. However, due to the highly complex molecular structure, the emulsification mechanism of sugar beet pectin is still unclear. In this study, the RG-Ⅰ region of sugar beet pectin was successfully isolated and characterized by chemical composition, FT-IR, TG/DTG, XRD and 1H NMR analyses. In addition, multiscale characterization techniques showed that RG-Ⅰ could form a much thicker and more elastic interfacial film than HG. This highly elastic interfacial film is crucial for the long-term emulsion stability. Moreover, our studies also showed that HG and RG-Ⅰ alone could not form an interfacial film as elastic as that of sugar beet pectin. This indicates that the smooth HG region and hairy RG-Ⅰ region of sugar beet pectin molecules are both necessary to form a thick and highly elastic interfacial film, and thus obtain a long-term stable emulsion.

Transcriptomic effects of the foraging gene shed light on pathways of pleiotropy and plasticity.

Genes are often pleiotropic and plastic in their expression, features which increase and diversify the functionality of the genome. The foraging (for) gene in Drosophila melanogaster is highly pleiotropic and a long-standing model for studying individual differences in behavior and plasticity from ethological, evolutionary, and genetic perspectives. Its pleiotropy is known to be linked to its complex molecular structure; however, the downstream pathways and interactors remain mostly elusive. To uncover these pathways and interactors and gain a better understanding of how pleiotropy and plasticity are achieved at the molecular level, we explore the effects of different for alleles on gene expression at baseline and in response to 4 h of food deprivation, using RNA sequencing analysis in different Drosophila larval tissues. The results show tissue-specific transcriptomic dynamics influenced by for allelic variation and food deprivation, as well as genotype by treatment interactions. Differentially expressed genes yielded pathways linked to previously described for phenotypes and several potentially novel phenotypes. Together, these findings provide putative genes and pathways through which for might regulate its varied phenotypes in a pleiotropic, plastic, and gene-structure-dependent manner.

Pushing the boundary of covalency in lanthanoid-tellurium bonds: Insights from synthesis, molecular and electronic structures of low-coordinate, monomeric europium(II) and ytterbium(II) tellurolates.

Owing to the strict hard/soft dichotomy between the lanthanoids and tellurium atoms, and the strong affinity of lanthanoid ions for high coordination numbers, low-coordinate, monomeric lanthanoid tellurolate complexes have remained elusive as compared to the lanthanoid complexes with lighter group 16 elements (O, S, and Se). This makes the development of suitable ligand systems for low-coordinate, monomeric lanthanoid tellurolate complexes an appealing endeavor. In a first report, a series of low-coordinate, monomeric lanthanoid (Yb, Eu) tellurolate complexes were synthesized by utilizing the secondary bonding interaction stabilized hybrid organotellurolate ligands. The reaction of bis[2-((dimethylamino)methyl)phenyl] ditelluride, 1 and 8,8'-diquinolinyl ditelluride, 2 with Ln0 metal (Ln = Eu, Yb) resulted in the formation of monomeric complexes [LnII(TeR)2(Solv)2] [R = C6H4(CH2NMe2)-2] [3: Ln = Eu, Solv = tetrahydrofuran; 4: Ln = Eu, Solv = acetonitrile; 5: Ln = Yb, Solv = tetrahydrofuran; 6: Ln = Yb, Solv = pyridine] and [EuII(TeNC9H6)2(Solv)n] (7: Solv = tetrahydrofuran, n = 3; 8: Solv = 1,2-dimethoxyethane, n = 2), respectively. Complexes 3-4 and 7-8 represent the first sets of examples of monomeric europium tellurolate complexes. The molecular structures of complexes 3-8 are validated by single-crystal X-ray diffraction studies.

Two novel metal complexes based on 2,2′-bipyridine and 2,4-dihydroxybenzoic acid: Synthesis, crystal structure and catalytic performance

To further enhance the catalytic performance of copper/lead 2,4-dihydroxybenzoate salt, two novel ternary complexes, Cu(C10H8N2)2(C7H5O4)·3H2O (complex 1) and [Pb(C10H8N2)(C7H5O4)2]·H2O (complex 2) were designed by introducing carbon framework ligand. The molecular structures of complexes 1 and 2 were determined by single crystal X-ray diffraction analysis. Both complex 1 and complex 2 were crystallized in the monoclinic crystal system. The difference is that the central Cu ion in complex 1 is connected to one oxygen atom of the carboxyl group of 2,4-dihydroxybenzoic acid, while the other 2,4-dihydroxybenzoic acid anion only acts as a counterion to balance the charge. But the central Pb ion in complex 2 is connected to four oxygen atoms of the carboxyl groups of two 2,4-dihydroxybenzoic acid and forms a six-coordinated structure. The Hirshfeld surface and associated 2D fingerprint analysis offer valuable insights into the intermolecular interactions within the crystal structure. Importantly, the thermal analysis results show that the thermal decomposition temperature of complex 1 is 204.1 °C, which has better thermal stability than complex 2. Furthermore, complex 1 showed remarkable catalytic activity on RDX compared to complex 2, and changed the thermal decomposition of RDX from melting decomposition to solid phase decomposition. This study will provide a new insight into development of combustion catalysts.

Hexacoordinated MIV (M=Ti, Zr, Hf) Tetrachlorido Complexes with Chelating Dithienylethane Based 1,2 Diketone Ligand – π‐Conjugation as Decisive Factor for Axial Chirality Mode

Abstract1,2‐bis(2,5‐dimethylthiophen‐3‐yl)ethane‐1,2‐dione (1, DTEthane) reacts with MCl4 metal precursors of group four (M=Ti, Zr, Hf) via coordination of the carbonyl groups. The molecular structure of complex 2–4 were determined in scXRD studies in the solid state and characterized by means of multi‐nuclear and multi‐dimensional NMR spectroscopy in solution. While the resulting titanium complex [TiCl4(DTEthane)] 2 shows a monomeric structure, where 1 binds in a bidentate fashion, complexes with a Zr (3) and Hf (4) center have dimeric scaffolds in which the ligands adopt a bridging mode. Quantum chemical calculations using density functional theory (G16, B97D3/def2‐TZVP) were used to evaluate the general trend of dimer formation (Ti<Zr<Hf). The molecular structures derived from both scXRD and the DFT optimized structures reveal the carbonyl groups in conjugation with the adjacent thiophene substituent. As a result, they are coplanar and rotation about the two C−C axes (C1−C7; C8−C9) is restricted allowing for only one chiral axis along C7−C8. This gains special importance with respect to previously described complexes carrying the closely related 1,2‐endiolato ligand (1,2‐bis(2,5‐dimethylthiophen‐3‐yl)ethene‐1,2‐diolate), in which no coplanarity of the thiophene rings to their neighboring metallacycle was observed allowing for two chiral axes. Noteworthy, further DFT calculations addressing the pathway of racemization found transition states, which are characterized by contrary rotations of both thiophene rings and a loss of conjugation rather than a direct rotation around the axis C7−C8.

A functionalized phosphorous tetrabenzotriazacorrole dye as a novel passivating agent of high-performance planar perovskite solar cells

Surface passivation is a crucial strategy to manage the film characteristics of solution-processed perovskite absorber layers, which greatly impact the photovoltaic properties of perovskite solar cells (PSCs). However, designing and synthesizing suitable passivating agents with required functional groups and solution-processability is challenging due to their complex molecular structure. In this study, we demonstrate a facile passivation technique using a functionalized phosphorous tetrabenzotriazacorrole dye (PTBC) for p-i-n PSCs. The tetrabenzotriazacorrole dye has amines and ether linkages that can closely interact with the undercoordinated Pb2+ with halogen vacancies through Lewis acid-base interactions, leading to a pinhole-free perovskite absorber layer with reduced trap density. Moreover, the central phosphorus of PTBC is functionalized with dimethoxy groups, which can provide a more hydrophobic surface in the perovskite absorber layer. Consequently, high-quality perovskite films (CsFAPbI3) prepared with PTBC exhibit improved optical, electrical, and morphological properties, as well as superior carrier transportation/recombination kinetics, boosting the power conversion efficiency of PSCs from 17.64 % to 20.08 %, with over 75 % of initial efficiency preserved after 1000 h of aging under ambient conditions. These results highlight PTBC as an effective surface passivation agent for perovskite absorber layers and emphasize the importance of suitable passivating agents in optimizing PSC performance.

Synthesis, characterization, X‐ray structure, DNA binding, antioxidant and docking study of new organotin(IV) complexes

Four new diorganotin(IV) complexes, including Me2SnL(1), Bu2SnL(2), Ph2SnL(3) and Oct2SnL(4), were synthesized by reacting R2SnCl2 (where R = Me, Bu, Ph, Oct) with N′‐(3,5‐dichloro‐2‐hydroxybenzylidene)‐2‐phenylacetohydrazide H2L. The synthesized ligand and complexes were structurally characterized by various techniques, including Fourier transform infrared (FT‐IR), 1H and 13C nuclear magnetic resonance (NMR) and mass spectrometry. The data suggested that tin–oxygen and tin–nitrogen bonds are formed during complex formation, confirming the coordination of ligand with dialkyltin(IV) moieties and the presence of penta‐coordinated structures. The single‐crystal X‐ray study was performed to confirm the molecular structure of complex 1, which revealed that the molecular structure is distorted towards square pyramidal geometry. The compound–DNA interaction was investigated via spectroscopic, electrochemical and molecular docking studies; the mode of interaction found in all cases was intercalative in nature. The complex 3 showed the highest binding ability with sodium salt of salmon sperm DNA (SS‐DNA) (1.93 × 105 M−1). The data obtained for DNA interaction studies from theoretical calculation via docking studies match well with those observed from spectroscopic and electrochemical analyses. Electrochemical and thermodynamic parameters, including diffusion coefficient, ∆H, ∆G and ∆S, were also calculated. The DPPH antioxidant results showed that complex 2 is an active antioxidant.

Deep Ultraviolet Photodetector: Materials and Devices

The application of deep ultraviolet detection (DUV) in military and civil fields has increasingly attracted the attention of researchers’ attention. Compared with the disadvantages of organic materials, such as complex molecular structure and poor stability, inorganic materials are widely used in the field of DUV detection because of their good stability, controllable growth, and other characteristics. Rapid advances in preparing high-quality ultrawide-bandgap (UWBG) semiconductors have enabled the realization of various high-performance DUV photodetectors with different geometries, which provide an avenue for circumventing numerous disadvantages in traditional detectors. Herein, the development history and types of DUV detectors are briefly introduced. Typical UWBG detection materials and their preparation methods, as well as their research and application status in the field of DUV detection, are emphatically summarized and reviewed, including III-nitride semiconductors, gallium oxide, diamond, etc. Finally, problems pertaining to DUV detection materials, such as the growth of materials, the performance of devices, and their future development, are also discussed.

Characterization Study of Dyes Photodegradation-Adsorption Products by TiO2-Chitosan Immobilized on Glass Beads using Flow System

Dyes have a complex molecular structure that is difficult to degrade and can persist for a long time in water bodies. This study examines more thoroughly the effectiveness of photodegradation-adsorption of dyes, kinetic aspects, isotherms, thermodynamics, identification of the structure of photodegradation products, and changes in environmental quality parameter values whose results are quite satisfactory. The combination of photodegradation-adsorption of dyes by TiO2-chitosan modified glass beads using a flow system has never been accomplished before. Flowing of the dye resulted in a dye degradation efficiency of 99%. The FESEM-EDX analysis shows that TiO2-chitosan has been coated onto the surface of the glass beads. R2 of kinetics MB, MO, RB are 0.99234, 0.9889, 0.9971, which were pseudo-first order. Qm, KL, R2 are 6.4382, 0.70533, 0.99923; 16.7364, 1.42059, 0.98816; 6.0078, 1.06973, 0.99889, respectively. The ∆H, ∆S, ∆S of -9.388, -0.024, -1.979; -27.182, -0.078, -3.592; -4.819, -0.017, 0.464 indicate the exothermic and spontaneous reaction. COD, TOC, pH, turbidity values have reached the threshold required by the government. The degradation products formed during the photodegradation-adsorption process were identified using LC-MS that the structure of the dye has been degraded to become simpler so that it is safely disposed of into the environment.

Selective Hydrodeoxygenation of Lignin‐Derived Vanillin via Hetero‐Structured High‐Entropy Alloy/Oxide Catalysts

The chemoselective hydrodeoxygenation of natural lignocellulosic materials plays a crucial role in converting biomass into value‐added chemicals. Yet their complex molecular structures often require multiple active sites synergy for effective activation and achieving high chemoselectivity. Herein, it is reported that a high‐entropy alloy (HEA) on high‐entropy oxide (HEO) hetero‐structured catalyst for highly active, chemoselective, and robust vanillin hydrodeoxygenation. The heterogenous HEA/HEO catalysts were prepared by thermal reduction of senary HEOs (NiZnCuFeAlZrOx), where exsolvable metals (e.g., Ni, Zn, Cu) in situ emerged and formed randomly dispersed HEA nanoparticles anchoring on the HEO matrix. This catalyst exhibits excellent catalytic performance: 100% conversion of vanillin and 95% selectivity toward high‐value 2‐methyl‐4 methoxy phenol at low temperature of 120 °C, which were attributed to the synergistic effect among HEO matrix (with abundant oxygen vacancies), anchored HEA nanoparticles (having excellent hydrogenolysis capability), and their intimate hetero‐interfaces (showing strong electron transferring effect). Therefore, our work reported the successful construction of HEA/HEO heterogeneous catalysts and their superior multifunctionality in biomass conversion, which could shed light on catalyst design for many important reactions that are complex and require multifunctional active sites.

Conversion of Lignocellulosic Wastes into Biofertilizer using Bacterial Consortium

Lignocellulosic biomass abundantly and ubiquitously occupies the earth. However, their complex molecular structure prevents their use as a source of organic material for fermentable sugars and nutrients to be used as foods, fertilizers and biofuels. For an efficient carbon cycle, microbial enzymes play a key role in slow biodegradation of lignocellulosic wastes in nature. Microbiological applications can enhance the rate of biodegradation to utilize agro-industrial and organic municipal solid wastes, containing up to 50% lignocellulose substrates, as an inexpensive and sustainable source of plant nutrients. With this hypothesis, the current study was carried out to prepare a consortium of lignocellulose degrading bacteria and use it to convert lignocellulosic substrates in garden, sugarcane, rice, cotton and fruit waste into biofertilizer. Overall, 7-14% reduction in cellulose and 3-6% reduction in lignin content, along with decrease in pH was observed on treatment of above wastes with microbial consortium in 42 days. In spite of the low conversion rates observed in our study, better root, shoot as well as leaf development was observed in moong seedlings grown in soil amended with biofertilizer (3:1 ratio) as compared to controls. Another interesting observation was the biofertilizers with low pH prepared from sugarcane wastes (pH 3.1) and fruit wastes (pH 3.6) supported plant growth more efficiently as compared to other biofertilizers (pH 5.0 to 5.7). Thus, in addition to feasible conversion of lignocellulosic wastes into biofertilizer, our study further suggests the use of selective wastes as raw material depending on the preference of plants for slightly acidic to neutral soil pH for growth.

The Synthesis and Biological Activity of Organotin Complexes with Thio-Schiff Bases Bearing Phenol Fragments.

A number of novel di- and triorganotin(IV) complexes 1-5 (Ph2SnL1, Ph2SnL2, Et2SnL2, Ph3SnL3, Ph3SnL4) with mono- or dianionic forms of thio-Schiff bases containing antioxidant sterically hindered phenol or catechol fragments were synthesized. Compounds 1-5 were characterized by 1H, 13C NMR, IR spectroscopy, and elemental analysis. The molecular structures of complexes 1 and 2 in the crystal state were established by single-crystal X-ray analysis. The antioxidant activity of new complexes as radical scavengers was estimated in DPPH and ABTS assays. It was found that compounds 4 and 5 with free phenol or catechol fragments are more active in these tests than complexes 1-3 with tridentate O,N,S-coordinated ligands. The effect of compounds 1-5 on the promoted oxidative damage of the DNA by 2,2'-azobis(2-amidinopropane) dihydrochloride and in the process of rat liver (Wistar) homogenate lipid peroxidation in vitro was determined. Complexes 4 and 5 were characterized by more pronounced antioxidant activity in the reaction of lipid peroxidation in vitro than compounds 1-3. The antiproliferative activity of compounds 1-5 was investigated against MCF-7, HTC-116, and A-549 cell lines by an MTT test. The values of IC50 are significantly affected by the presence of free antioxidant fragments and the coordination site for binding.

Regioselective Difunctionalization and Annulation of Ynamide

AbstractThe use of ynamides in organic synthesis has gained significant attention due to their ability to provide access to complex molecular structures through transformations such as 1,2‐difunctionalization and annulation reactions. These reactions enable the formation of highly functionalized N‐bearing olefins and unusual N‐bearing heterocycles. In this minireview, we present a systematic overview of the regioselective difunctionalization and annulation reactions of ynamides. We discuss the multi‐component reactions, and radical‐triggered functionalizations across the ynamides carbon–carbon multiple bonds and the use of bifunctional reagents in annulation of ynamides, highlighting their potential in expanding the substrate scope. Furthermore, we provide insights into the mechanistic breakthroughs that have been achieved in recent years in the development of these reactions. Finally, we emphasize the promising future prospects of ynamides as versatile building blocks for the synthesis of complex molecular architectures.

Regioselective Difunctionalization and Annulation of Ynamide.

The use of ynamides in organic synthesis has gained significant attention due to their ability to provide access to complex molecular structures through transformations such as 1,2-difunctionalization and annulation reactions. These reactions enable the formation of highly functionalized N-bearing olefins and unusual N-bearing heterocycles. In this minireview, we present a systematic overview of the regioselective difunctionalization and annulation reactions of ynamides. We discuss the multi-component reactions, and radical-triggered functionalizations across the ynamides carbon-carbon multiple bonds and the use of bifunctional reagents in annulation of ynamides, highlighting their potential in expanding the substrate scope. Furthermore, we provide insights into the mechanistic breakthroughs that have been achieved in recent years in the development of these reactions. Finally, we emphasize the promising future prospects of ynamides as versatile building blocks for the synthesis of complex molecular architectures.

Role of Molecular, Crystal, and Surface Chemistry in Directing the Crystallization of Entacapone Polymorphs on the Au(111) Template Surface.

The pharmaceutical compound entacapone ((E)-2-cyano-3-(3,4-dihydroxy-5-nitrophenyl)-N,N-diethylprop-2-enamide) is important in the treatment of Parkinson's disease, exhibiting interesting polymorphic behavior upon crystallization from solution. It consistently produces its stable form A with a uniform crystal size distribution on the surface of an Au(111) template while concomitantly forming its metastable form D within the same bulk solution. Molecular modeling using empirical atomistic force-fields reveals more complex molecular and intermolecular structures for form D compared to form A, with the crystal chemistry of both polymorphs being dominated by van der Waals and π-π stacking interactions with lower contributions (ca. 20%) from hydrogen bonding and electrostatic interactions. Comparative lattice energies and convergence for the polymorphs are consistent with the observed concomitant polymorphic behavior. Synthon characterization reveals an elongated needle-like morphology for form D crystals in contrast to the more equant form A crystals with the surface chemistry of the latter exposing the molecules' cyano groups on its {010} and {011} habit faces. Density functional theory modeling of surface adsorption reveals preferential interactions between Au and the synthon GA interactions of form A on the Au surface. Molecular dynamics modeling of the entacapone/gold interface reveals the entacapone molecular structure within the first adsorbed layer to show nearly identical interaction distances, for both the molecules within form A or D with respect to the Au surface, while in the second and third layers when entacapone molecule-molecule interactions overtake the interactions between those of molecule-Au, the intermolecular structures are found to be closer to the form A structure than form D. In these layers, synthon GA (form A) could be reproduced with just two small azimuthal rotations (5° and 15°) whereas the closest alignment to a form D synthon requires larger azimuthal rotations (15° and 40°). The cyano functional group interactions with the Au template dominate interfacial interactions with these groups being aligned parallel to the Au surface and with nearest neighbor distances to Au atoms more closely matching those in form A than form D. The overall polymorph direction pathway thus encompasses consideration of molecular, crystal, and surface chemistry factors.

Tuning the Diradical Character of Pentacene Derivatives via Non-Benzenoid Coupling Motifs.

The development of functional organic molecules requires structures of increasing size and complexity, which are typically obtained by the covalent coupling of smaller building blocks. Herein, with the aid of high-resolution scanning tunneling microscopy/spectroscopy and density functional theory, the coupling of a sterically demanded pentacene derivative on Au(111) into fused dimers connected by non-benzenoid rings was studied. The diradical character of the products was tuned according to the coupling section. In particular, the antiaromaticity of cyclobutadiene as the coupling motif and its position within the structure play a decisive role in shifting the natural orbital occupancies toward a stronger diradical electronic character. Understanding these structure-property relations is desirable not only for fundamental reasons but also for designing new complex and functional molecular structures.

A silicone coating containing natural borneol fluorinated side chains with excellent static antifouling properties

Nowadays, the development of sustainable nontoxic antifouling coatings is urgent. In this work, the isobornyl as antifouling groups and dodecfluoroheptyl were introduced into the silicone side chains to prepare the environment-friendly silicone antifouling coatings. The synergistic effect of natural borneol and dodecfluoroheptyl improved the static antifouling ability of silicone coating. The coatings exhibited good optical clarity (>92%, 400–800 nm), high adhesion (>2 MPa, steel plates) and excellent fouling release and self-cleaning ability. For example, PDMS-F-PIBO-23 coating had excellent antibacterial and antifouling activities. It’s antibacterial resistance to marine bacteria (Pseudomonas sp.) reached 95.6%, which reduced the coverage area of biofilm by 86.9%, and effectively prevented the adhesion of diatoms. This remarkable antibacterial and antifouling performance was attributed to the complex molecular structure of natural non-toxic borneol and the enrichment of fluoropolymers. Field tests at Yellow Sea showed that the coating had good antifouling ability and could be used for >6 months. Most importantly, compared with traditional coatings containing toxic fungicides, the coating is less harmful to the marine ecological balance. This research provides more possibilities for marine antifouling coatings design and preparation which is expected to be applied in marine, medical and other antipollution fields.

Phytochemical and thickening properties of the mucilage of Malachra alceifolia jacq., in a shampoo formulation

The feasibility of the using of mucilages as viscous hydrocolloids in order to reduce dependence on inorganic products that are unfriendly to the environment, is a necessity that the scientific community must take advantage on behalf of development of new products. The aim was to determine the phytochemical components and thickening capacity of mucilage as a hydrocolloid in a shampoo formula. Phytochemical sieve was done by coloration, precipitation and flotation reactions. Mucilage extraction was performed by hydration-maceration of crushed stems according to experimental design (three factors and two levels) and controlled by the viscosity response variable. For the shampoo, a design of was used (two factors and two levels), evaluated with viscosity response variables and lather formation, results that were tabulated with the statistical software statgraphics plus. The results show in the hydrocolloid the presence of tannins, alkaloids, triterpenes. Its thickening capacity due to the significant viscosity of the hydrocolloid (1186 mPa.s). The viscosity of the shampoo between 1020 and 1460 mPa.s and the amount of foam (213 ml) that reward the quality. It is concluded that, the complex molecular structure and abundant presence of mucilage in its natural state in the stems of Malachra alceifolia Jacq allows the hydrocolloid obtained to have a great viscosifying and moisturizing capacity with an almost neutral pH, qualities that affect the quality of the shampoo and are suitable for commercial products with friendly features to the environment; being promoted as a raw material for formulations of other personal hygiene products with an important projection of immediate application in the pharmaceutical and cosmetic industry.