Improvement of the cold-flow and cold storage properties of diesel fuels is achieved using depressant-dispersant additives composed of cold-flow improvers (CFIs) and wax anti-settling additives (WASAs). The products of the reactions of linear alpha-olefins with maleic anhydride (MA), treated by secondary fatty amines, efficiently provide low-temperature storage stability of diesel fuels. The mixtures of these WASAs with ethylene/vinyl acetate copolymer (EVA) were successfully commercialized as a part of diesel additive package. In the present study, we suggested the use of alpha-olefin vinylidene dimers instead of linear alpha-olefins as a starting compounds for the synthesis of WASAs. Alder-ene reaction and free-radical copolymerization of alpha-olefins or alpha-olefin dimers with MA were studied, considering reaction mechanisms with the use of DFT modeling. The nature of the solvent proved important for copolymerization, the ability of tetralin to act as a chain transfer agent was detected experimentally (naphthalene formation) and explained theoretically (DFT). Branched WASAs were obtained by treating Alder-ene adducts or copolymers of C6-C18 alpha-olefin dimers and MA with secondary fatty amines. The mixtures of alpha-olefin dimer based WASAs (100 ppm) with EVA (200 ppm) decreased CFPP of different diesel fuels by 10-17 degrees C (9-13 degrees C for linear alpha-olefin derivatives) and provided cold storage stability at a temperatures of 5 degrees C below the cloud point of diesel fuels within 16 h.

The promoting ability of the organophosphines for the Pd(OAc)2/p-toluenesulfonic acid catalytic system in the methoxycarbonylation reactions of cyclohexene and 1-octene has been studied. Both reactions proceeded regioselectively for esters, achieving yields of up to 97.6% under mild conditions. Using the nonempirical ab initio method, the natural bite angles of diphosphines in complexes with the Pd-center have been calculated. It has been established that a high value of this angle is a factor in high reaction parameters - the rate and the yields of target product. However, the highest value of TOF in the model cyclohexene reaction has been obtained in the case of the palladium-diphosphine complex with a middle value for this angle among the tested diphosphines. It has been established that the relative P-promoters activity is influenced not only by their structure, but also by the alkene structure. Apparently, the presence of electron-donating p-MeO-groups in Ph-substituents at P-atoms in the diphosphine determines its low activity compared to its close analogues, although the donor and acceptor electronic effects of substituents at P-atoms in diphosphine mostly ambiguously act the parameters of alkoxycarbonylation.

Isotactic copolymers of But-1-ene with 'Bu,Al-protected undec-10-en-1-ol were synthesized at comonomer contents of 3.6, 5.2 and 13.0 mol96. The C-1-symmetric ansa-heterocene [Me Si(-2,4,7-trimethylinden-1-yl) ( 2,5-dimethyl-7H-cyclopenta [1,2-b:4,3-b]dithiophen-7-yl)]ZrCl; (Zr1), activated by Bu,Al and MMAO-12 (of 20 equiv. each), demonstrated activity of 4-103 kg mol & sup1;ch at a [(co)monomer]/[Zr1] ratio of 105/1. The mo-lecular weight (Mw) of the copolymers (SBC, 120 degrees C in 1,2,4-CHCl3) was 1-1.2 MDa, which is attributed to intermolecular hydrogen ponding. Subsequent treatment with AcCl (72h at 90 degrees C in toluene) resulted in for-mation of the -OAc functionalized copolymers (M105-326 kDa) in quantitative yields. The presence of --OH groups promoted the Form II to Form I transition in IPB, while the formation of Form III in the presence of -OAc groups was revealed by XRD and DSC. Whereas -OH-containing copolymers show a tendency toward intermo-lecular hydrogen bonding which distorts experimental M, values and increases the copolymer viscosity, OAc-containing counterparts alle materials with the low viscosity necessary for melt processing. Hydroxylated poly (but-1-ene) with a 3.6m 196 -OH group content demonstrates increased stretchability and toughness, indi-cating its high impact resistance and energy absorption capacity. Acetylated poly(but-1-ene)s can be used as hot-melts or smart pressure-sensitive adhesives, depending on the content of polar comonomer.

For the first time, coordination cooligomers of dec-1-ene with iBu2Al-protected biobased undec-10-en-1-ol (M1-Al) and dec-9-en-1-ol (M2-Al) were obtained using new ansa-heterocene catalyst, [ethylenebis(η5–2,5-dimethyl-7H-cyclopenta[1,2-b:4,3-b’]dithiophen-7-yl)] dichlorozirconium (IV) (Zr1). Cooligomers with Mn = 1.0–10.9 kDa, ÐM = 1.6–2.5, and 0.12–4.0 mol% –OH groups had a KV100 = 25.6–144.9 cSt and VI = 179–232. The high-temperature viscosity characteristics of polar cooligomers were predominantly influenced by Mn, while the effect of the presence of –OH groups emerged only when the temperature was decreased to −40 °C. Thus, only low temperatures ensured the strong interactions between –OH groups, resulting in increased viscosity and higher pour point. Nevertheless, the polar cooligomers demonstrated higher wettability of steel surfaces at 25 °C and provided more efficient lubrication in comparison with oligo(dec-1-ene)s, especially under high loads, inducing a transition from mixed to elastohydrodynamic friction. Polar dec-1-ene cooligomers, possessing excellent viscosity characteristics (VI, KV) comparable to those of Group IV base oils, inherently contain the structural fragments that act as a friction modifiers. The integration of friction-modifying moieties into the lubricant oligomers guarantees their structural uniformity, thereby avoiding phase separation, structural instability, and performance variability under fluctuating operational temperatures and pressures. Further studies of similar oligomers can form the basis for the development of advanced lubricant formulations.

Poly(L-lactic acid) (PLLA) is the most synthetically available polymer, produced from renewable raw materials. Biodegradability, biocompatibility and practical molding temperatures (Tm ∼ 170–180 °C) are key advantages of PLLA, but its slow crystallization kinetics, limited thermal stability, modest strength and elasticity complicates preparation and limits the applicability of PLLA-based products. Stereocomplexation of PLLA with enantiomeric poly(D-lactic acid) (PDLA) significantly improves the properties of bioplastics, and over almost four decades after discovery of stereocomplexed PLA (SC-PLA) similar materials were extensively studied. However, high melting temperature of SC-PLA (Tm ∼ 220–230 °C) makes it difficult to manufacture products from 1:1 PLLA/PDLA blends from the melt. The solution to this problem is the use of L-lactate copolymers: deviations from PLLA stoichiometry and/or stereochemistry expands the range of material characteristics and applications. One of the prospective ways of the further design of L-lactate copolymers, capable of stereocomplexation, is based in the use of poly(L-lactic-co-glycolic) acids (L-PLGAs). In the present review, we examined the main synthetic approaches to lactate-containing polymers, the basic patterns of SC-PLA formation and the main characteristics of SC-PLAs and composites on their base. The issues of the product molding and material applications are considered in the light of the use of non-stoichiometric PLAs (stat- and block-copolymers, PLA grafts, and others). Special attention is given to PLGAs with increased statisticity or possessing ideal alternating structure as a promising candidates for the development of next-generation stereocomplexed biodegradable materials. The recent progress in development of ’non-acidifying’ PLGAs, based on the use of L-methylglycolide (L-MeGL, Tm = 100–140 °C for poly(L-MeGL) and 188–212 °C for corresponding stereocomplex) something prompted this work. The present review is devoted to the practical outcomes of SC formation in light of chemical design of (co)polymers and composites in a broad sense (monomer & catalyst design → (co)polymer preparation/functionalization/grafting → material blending/molding → improved properties & new applications).

A series of tris(triphenylcyclopentadienyl) ate-complexes [CpPh33LnCl]−[MLn]+ (Ln = La, Ce, Pr) MLn = Li(THF)4 (Ln1), K(18-crown-6)(THF) (Ln2), Na(THF)6 (La3) were synthesized by the straightforward salt-metathesis method. All the structural types have been studied by single-crystal X-ray diffraction. The formation of complexes results from the concerted arrangement of the phenyl substituents of the three bulky triphenylcyclopentadienyl ligands respect to each other. Synthesis of tris(triphenylcyclopentadienyl) complexes of lanthanides with an ionic radius less than that of praseodymium could not be achieved. In conditions unfavorable for formation of the ate-complex, only La3, can be obtained, cerium reaction results in an inseparable mixture of compounds, while praseodymium yields the bis(cyclopentadienyl) complex [CpPh32PrCl(THF)] (Pr4).

To reduce the time of postoperative recovery and to prevent post-surgical complications, biocompatible synthetic materials with osteoconductive and osteoinductive properties are used as bone substitutes in large bone defect management. A simplified biomimetic approach to similar materials is based on the use of an inorganic filler, a polymer matrix, and a compatibilizer, mimicking the composition of the natural bone. Based on plate-like micro-sized carbonated hydroxyapatite (pCAp), we prepared compression-molded samples optionally containing an additional polyester component (poly(ε-caprolactone) PCL, poly(L-lactide) PLLA, or poly(L-methylglycolide) PLMG); syntheticblock copolymers comprising fragments of the corresponding polyester and poly(ethylene phosphoric acid) (PEPA) were also prepared and studied asa ‘two-in-one’ polymer matrix/compatibilizer. Bone regeneration experiments involving a three-month rat tibial defect model were conducted with 250–500 μm granules of the composites. Comparative studies of the introduction of the polyester-b-PEPA copolymer into composites revealed a positive effect, which manifests itself in accelerated bone regeneration, which further intensified for pCAp/PEPA-b-PLMG. The latter composite formulation was used to study the results of the introduction of cerium into the filler. One-month experiments with pCAp, CePO4-doped pCAp, and composites of these inorganic fillers with PEPA-b-PLMG were conducted. For the first time, a positive synergistic effect of the presence of cerium and PEPA in the composite, which appeared in substitution of the implant material by two-thirds of newly formed partly matured bone, was observed four weeks after surgery.

Fatty amines (FAMs), aliphatic amines possessing a mostly linear C8+ hydrocarbon fragments, are large-capacity chemicals widely used in production of detergents, emulsifiers, adjuvants, fabric softeners, fuel and oil additives, corrosion inhibitors, etc. The current technologies of FAMs are based on fatty acids (nitrile process) and alcohols, obtained from triglycerides and petrochemical feedstocks. Alternative catalytic approaches to amines, intensively studied in recent decades, are direct amination of alkenes, reductive amination and aminomethylation of carbonyl compounds, hydrogen-borrowing amination of alcohols, and single-stage triglyceride or waste conversion. However, only a fraction of recent top-rated works was related to the synthesis of FAMs. In the present review, we describe and discuss above-mentioned current and prospective catalytic approaches to FAMs. The advantages and shortcomings of these approaches are evaluated from the practical point of view, indicating the most promising directions of the further industrially oriented research.

Lanthanide tris complexes with unsubstituted and diarylcyclopentadienyl ligands have been synthesized and studied by single crystal X-ray diffraction analysis and optical spectroscopy. It is shown that the coordination surrounding formed by three Cp ligands can be an effective tool to depress the 4f5d configuration energy down as a result for Ce complexes the luminescence at 610 nm and energy of 5d1 level as 470 nm were observed. The energy transfer scheme S → 4f5d → 4ff* realized in the designed complexes has been deciphered by the comparing the spectroscopic data for Ce3+, Pr3+, Gd3+ and Tb3+ ions. The spectroscopic redshift of the first electric dipole-allowed 4f5d transition of the Ce3+ ion was interpreted by combining the centroid shift and the crystal-field splitting for organometallic compounds at the first time.

Poly(lactic-co-glycolic acid)s (PLGAs) hold considerable significance for their biomedical applications. Biodegradation and mechanical properties of PLGAs and PLGA-based composites are strongly influenced by lactate/glycolate (L/G) ratio in copolymers, molecular weight characteristics and microstructure of PLGAs. The common approach to PLGAs is based on ring-opening copolymerization of lactides and glycolide, the products of which contain long (L)n and (G)n segments. An efficient but expensive approach to PLGAs with given l-G sequences is a segmer assembly polymerization that is hardly applicable for the synthesis of high-MW PLGAs. In the present work, for the first time we synthesized lactate-enriched PLGAs using ring-opening copolymerization of l-lactide (l-LA) with l-methylglycolide (l-MeGL) in 85:15 and 70:30 molar ratios, resulting in l-PLMG 85/15 and l-PLMG 70/30 copolymers. l-PLGA 85/15 with the same L/G ratio as in PLMG 70/30 was synthesized by ring-opening copolymerization of l-LA with glycolide as a sample for a comparison. According to 1H and 13C NMR data and [α]D measurements, l-MeGL-based PLGAs had a unique microstructure, e.g. macromolecules of l-PLMG 85/15 consisted of Ln sequences with single G insertions. Composites of PLLA and three samples of PLGAs with plate-like carbonated apatite (pCAp) containing 25 and 50 wt.% of the filler were prepared. Rectangular specimens from (co)polymers and (co)polymer composites were obtained by injection molding and studied. Due to the absence of highly reactive (G)n fragments, l-PLMG 85/15 and PLMG 70/30-based materials demonstrated higher thermal and hydrolytic stability, mechanical testing showed that l-MeGL-based copolymers provide better maintaining of the bending strength in comparison with l-PLGA 85/15 matrix.

N-Boc-protected morpholin-2-ones have been synthesized with a high to moderate yields from the natural l-amino acids (Ala, Val, Leu, Phe, Tyr). These compounds can find application in the development of biodegradable and biocompatible polymeric vehicles for DNA and RNA delivery.

Lanthanide complexes [CpXLnCl2(Me3tach)]n (Ln = Tb, Gd; CpX = Cp, CpPh2, CpPh4; Me3tach = 1,3,5-trimethyl-1,3,5- triazacyclohexane; n = 1, 2), containing cyclopentadienyl (Cp), 1,3-diphenylcyclopentadienyl (CpPh2) and tetraphenyl- cyclopentadienyl (CpPh4) anions as ν-bonded antenna ligands, have been synthesized. A combined analysis of quantum chemical, optical and X-ray diffraction data has shown that the introduction of phenyl groups into the Cp ring leads to the inevitable appearance of intraligand charge transfer states due to the nonequivalence of the phenyl rings.

Проанализированы публикации отечественных и зарубежных авторов, посвященные исследованиям каталитических систем Циглера‒Натта на основе неодима, ванадия и титана, модифицированных хлорорганическими соединениями и используемых в синтезе полиолефинов и полидиенов. Проведен анализ патентной литературы и проанализированы основные тренды развития в области металлокомплексного катализа с использованием хлорорганических соединений. Рассмотрены преимущества и недостатки подобных каталитических систем по сравнению с классическими немодифицированными катализаторами, в которых в качестве источника хлора применяются алкил-алюминийхлориды. Авторами подробно проанализированы опубликованные данные о роли атома хлора как лиганда в активных центрах полимеризации олефинов и диенов. Выявлена и описана роль моно- и полихлорированных органических соединений в неодимовой, ванадиевой и титан-магниевой каталитических системах.

Sandwich SiMe2-bridged ansa-complexes of zirconium, containing heterocycle-fused eta 5-cyclopentadienyls, de-rivatives of 2,5-dimethyl-7H-cyclopenta[1,2-b:4,3-b']dithiophene (2), 5,10-dihydroindeno[1,2-b]indole (3) and 5,6-dihydroindeno[2,1-b]indole (4)- 'heterocenes' - catalyzed ethylene homopolymerization and ethylene/oct-1-ene (E/O) copolymerization in the presence of triisobutylaluminum (TIBA) without MAO and perfluoroaryl borate activators, the benchmark bis(eta 5-fluorenyl) complex 1 was virtually inactive under these conditions. In the absence of MAO, E/O copolymerization resulted in a formation of copolymers not containing EOOE frag-ments even at E/O ratio of 2.4. Addition of 10 eq. of MMAO-12 resulted in increase of both catalytic activities of 2-4 and oct-1-ene incorporation. E/O copolymers POE-05 (obtained on TIBA activated precatalyst 2) and POE-17 (obtained on TIBA/MMAO-12 activated precatalyst 4) were not inferior to the best commercial E/O co-polymers in physico-mechanical characteristics at-45 degrees C. Extrusion blends of POE-05 and POE-17 with high density polyethylene (HDPE) demonstrated high impact strength and frost resistance.

Despite large-scale investigations of homogeneous single-site metallocene catalysts and systems based on them, there are still unsolved problems related to the control of their activity and chemo- and stereoselectivity. A solution to these problems is required to develop efficient methods for the synthesis of practically useful products of alkene transformations, such as dimers, oligomers, and polymers. Here we studied the catalytic activity of structurally diverse zirconocenes (L2ZrCl2, L = Cp, C5Me5, Ind, L2 = Me2CCp2, Me2SiCp2, Me2C2Cp2, rac-Me2CInd2, rac-H4C2Ind2, BIPh(Ind)2, H4C2[THInd]2), and co-catalysts activating the system, namely HAlBui2, MMAO-12, and (Ph3C)[B(C6F5)4], at low activator/Zr ratios in a 1-hexene oligomerization reaction. The influence of catalyst structure and system composition on the alkene conversion, the type of products, and the reaction stereoselectivity were investigated. The composition of hydride intermediates formed in the L2ZrCl2–HAlBui2–activator system (L2 = ansa-Me2CCp2, Ind) was studied by NMR spectroscopy. Participation of the bis-zirconium hydride complex as the precursor of catalytically active sites of the alkene dimerization reaction was shown.

Prospective method of poly(bisphenol A carbonate) (BPAC) waste processing is based on catalytic glycolysis, combining recycling to bisphenol A (BPA) and upcycling with a formation of cyclic carbonates. With the aim of developing efficient solvent-free glycolysis of BPAC we studied catalytic behavior of Li, Na, K, Mg, Ca and Zn acetates in the reaction of BPAC with ethylene glycol (EG). With the use of EG as reagent and reaction media at 180 degrees C, down to 0.01 wt% of Mg(OAc)(2) and Zn(OAc)(2) catalyzed full conversion of BPAC to BPA and ethylene carbonate within 1 h. Acetates of alkali metals demonstrated lower activities and selectivities, Ca(OAc)(2) was found to be almost inactive. DFT optimization of the metal complexes with components of the reaction mixture allowed to explain low catalytic activity of Li, Na, K and Ca acetates by relative stability of inactive metal phenolates, whereas Mg and Zn acetates tend to form active glycolate species and phenol. Theoretical in-vestigations of the mechanism of Mg(OAc)2 and Zn(OAc)2-catalyzed glycolysis of the model substrate diphenyl carbonate have determined the sequence of the reaction intermediates and transition states, thereby explaining the high catalytic activities of Mg and Zn acetates by relatively low values of the activation barriers amounted to similar to 15 kcal/mol in G scale. Comparative experimental studies of 1,2-, 1,3-, 1,4-diols and glycerol in glycolysis of BPAC have demonstrated high efficiency of Mg(OAc)(2) and Zn(OAc)(2) catalysts in the amount of less then 0.1 wt%, the yields of BPA exceeded 90%. Along with that, the high yields of cyclic carbonates were achieved when using 1,2-diols and 1,3-diols, containing alkyl substituents in alpha-position to -OH group.

The publications of domestic and foreign researchers devoted to studies of Ziegler–Natta catalytic systems based on neodymium, vanadium, and titanium modified with organochlorine compounds and used in the synthesis of polyolefins and polydienes are scrutinized. The relevant patent literature has been explored, and the main development trends in the field of metal complex catalysis using organochlorine compounds have been analyzed. The advantages and disadvantages of such catalytic systems are considered in comparison with classical unmodified catalysts, in which alkylaluminum chlorides are used as a source of chlorine. The authors analyzed in detail published data on the role of the chlorine atom as a ligand in active sites for the polymerization of olefins and dienes. The role of mono- and polychlorinated organic compounds in neodymium, vanadium, and titanium–magnesium catalytic systems has been revealed and described.

In order to elucidate the dependence of the structure and reactivity of the bimetallic hydride intermediates formed in the systems metallocene—organoaluminum compound—activator on the nature of the transition metal atom and ligand environment, we used NMR spectroscopy to study reactions of a series of L2MCl2 complexes (M = Hf, Zr; L2 = Cp2, (CpMe)2, ansa-(Me2C)2Cp2, ansa-Me2CInd2) with HAlBui2 and MMAO-12 activator. As a result, M, Al-bimetallic intermediates containing [L2MH3] and [(L2M)2H3] type moieties were detected for both hafnium and zirconium complexes with cyclopentadienyl ligands. The [L2ZrH3] type structure predominates in the system based on the ansa-bis-indenyl zirconium complex. The detected complexes provide associates with MMAO-12 [L2MH3]·MAO and [(L2M)2H3]·MAO. The MAO-associated intermediates of the [(L2M)2H3] type are precursors of the catalytically active sites for alkene dimerization. In the system based on ansa-bis-indenyl zirconium complex, the intermediate of the [L2MH3] type affords a set of hydride structures, presumably cationic, which lead to alkene oligomerization.

In the present work, monosubstituted glycolides (G2-G4) derived from the (L)-tyrosine-based glycolide G1 and containing -CH2C6H4OR substituents (R = decanoyl, oleoyl, C(O)CH(n-C6H13)(n-C8H17)) have been used to design biodegradable and biocompatible lipophilic blocks in N-BOC-morpholin-2-one (M1)-based Charge-Altering Releasable Transporters (CARTs). Copolymers of dodecyl carbonate C1 (the `benchmark' lipophilic comonomer) and M1, having direct (P1) or inverse (P2) block sequences; copolymers of G2-G4 and M1, having inverse block sequences and irregular, head-to-head in places, microstructures of the poly(glycolide) blocks (P3-P7); and copolymers of G2 and M1, having solely alternating head-to-tail microstructures of the poly(glycolide) blocks and direct (P8) or inverse (P9) block sequences, have been synthesized. DLS studies have shown that, after deprotection, the copolymers P1'-P9' form liposomal particles in aqueous medium, differing considerably in their colloidal behavior, which depended on the length of the polyamine fragment and the nature of the lipophilic block. The ability of P1'-P9' to deliver the plasmid pEGFP-N1 into cultured HEK293T cells (transfection efficiency) has been assessed at N/P ratios of the corresponding polyplexes in the range 1:1-50:1 by flow cytometry and further confirmed by fluorescence microscopy. Transfection experiments have demonstrated that the CARTs P1', P4', and P6', containing ten (2-oxyethyl)glycine fragments, are about four times more efficient in delivering pDNA than commercial agents (Lipofectamine T 3000, PEI MAX, X-tremeGENE (TM) 9, and GenJet (TM) In Vitro DNA Transfection Reagent). A correlation between the results of those studies and DLS / zeta-potential measurements has been established for P1' and P4': the transfection is efficient, if N/P ratios are equal to those favoring zeta-potential inversion at physiological pH. We conclude that glycolide-based CARTs show significant promise for further development as non-viral NA delivery vehicles and that DLS should be regarded as an efficient method of primary screening of amphiphilic copolymers, as well as copolymer-NA complexes and formulations thereof.