Cl Units Research Articles

Simulation of two-step redox recycling of non-stoichiometric ceria with thermochemical dissociation of CO2/H2O in moving bed reactors – Part II: Techno-economic analysis and integration with 100 MW oxyfuel power plant with carbon capture

This paper presents the model of a solar thermochemical looping CO2/H2O dissociation (CL) unit with commercial ceria as the redox oxygen carrier. The CL unit is integrated in an oxy-fuelled combined cycle power plant as an add-on unit to a 100 MW oxy-fuelled natural gas power plant with carbon capture. The efficiency benefit obtained was investigated. A moving bed counter-current reactor model, developed in ASPEN Plus®, consisting of a series of rigorous continuous stirred reactors (RCSTRs) was used for the simulation of both reduction and oxidation reactors of the CL unit. A kinetic subroutine was developed in FORTRAN and linked with each RCSTR for both reduction and oxidation reactions. It is found that the efficiency of the CL unit varies widely with reduction reactor temperature and operating pressure. Considering three different compositions of the feed gas to the oxidation reactor, the CL unit efficiency is obtained as: 35.41% with CO2 only; 30.84% with H2O only; and 35.26% for a mixture of 86% CO2 and 14% H2O. The lower efficiency for H2O-only operation is due to the heat requirement for water vaporization and the higher compression work required for compressing H2 than CO. The maximum solar to electrical efficiency for the whole add-on unit is found to be 25.44% with a reduction reactor operating at a temperature of 1600 °C and 10−7 bar vacuum pressure. With 0.5 m3 reduction reactor volume and 5 m3 oxidation reactor volume, the maximum net electricity produced by the CL add-on unit is 12.85 MWe. Economic analysis revealed that the major contributors to total plant cost are the hydrogen compressor and solar field and tower, which are the 19% and 39% of the total equipment cost, giving a specific overnight capital cost of 12,136 $/kW with an LCOE of 1321 $/MWh with a capacity factor of 21%. The LCOE drops to 628 $/MWh with a carbon tax of 80 $/tonne of CO2 and increased capacity factor of 26%.

Synthesis of Trimetallic (HPd@M2Au8)3+ Superatoms (M = Ag, Cu) via Hydride-Mediated Regioselective Doping to (Pd@Au8)2.

We have recently reported that hydride (H–) doped superatom (HPd@Au8)+ protected by eight PPh3 ligands selectively grew into (HPd@Au10)3+ by the nucleophilic addition of two Au(I)Cl units. In the present study, (HPd@Au8)+ was successfully converted to unprecedented trimetallic (HPd@M2Au8)3+ superatoms (M = Ag, Cu) by controlled doping of two Ag(I)Cl or Cu(I)Cl units, respectively. Single-crystal X-ray diffraction analysis demonstrated that two Ag(I) or Cu(I) ions were regioselectively incorporated. Theoretical calculations suggested that hydrogens in (HPd@M2Au8)3+ (M = Au, Ag, Cu) occupy the same bridging site between the central Pd atom and the surface Au atom. (HPd@Ag2Au8)3+ exhibited photoluminescence at 775 nm, with the enhanced quantum yield of 0.09%, although it is structurally and electronically equivalent with (HPd@Au10)3+. This study demonstrates that hydride-mediated growth process is a promising atomically-precise bottom-up synthetic method of new multimetallic superatoms.

Towards room temperature operation of all-solid-state Na-ion batteries through polyester–polycarbonate-based polymer electrolytes

In an ambition to develop solid-state Na-ion batteries functional at ambient temperature, we here explore a novel electrolyte system. Polyester-polycarbonate (PCL–PTMC) copolymers were combined with sodium bis(fluorosulfonyl)imide salt (NaFSI) to form solid polymer electrolytes for Na-ion batteries. The PCL–PTMC:NaFSI system demonstrated glass transition temperatures ranging from −64 to −11 °C, increasing with increasing salt content from 0 to 35 wt%, and ionic conductivities ranging from 10−8 to 10−5 S cm−1 at 25 °C. The optimal salt concentration was clearly dependent on the level of crystallinity, which was largely determined by the CL content. At 70 and 80 mol% CL, the PCL–PTMC:NaFSI system was fully amorphous and exhibited high conductivities at lower salt concentrations. When the CL content was increased to 100 mol%, high ionic conductivities were instead observed at high salt concentrations. A decent transference number of ca. 0.5 at 80 °C was obtained for a polymer film containing 20 mol% CL units and 25 wt% NaFSI. Finally, a HC|80-2025|Na2−xFe(Fe(CN)6) all-solid-state polymer electrolyte full cell was assembled to demonstrate the practical application of the material and cycled for more than 120 cycles at ∼22 °C.

An NHC-CuCl functionalized metal-organic framework for catalyzing β-boration of α,β-unsaturated carbonyl compounds.

A microporous metal-organic framework functionalized with in situ generated NHC-CuCl units (1) has been successfully synthesized from a novel imidazolium-containing ligand. In particular, the MOF 1 can catalyze β-boration of α,β-unsaturated carbonyl compounds, while the isoreticular version of 1 (1-im) modified with only imidazolium moiety cannot. This work demonstrates for the first time the heterogeneous catalysis of NHC-Cu(i)Cl within a MOF solid.

Solvent‐free ring‐opening polymerization of lactones with hydrogen‐bonding bisurea catalyst

ABSTRACTDevelopment of effective organocatalysts for the living ring‐opening polymerization (ROP) of lactones is highly desired for the preparation of biocompatible and biodegradable polyesters with controlled microstructures and physical properties. Herein, a new class of hydrogen‐bond donating bisurea catalysts is reported for the ROP of lactones under solvent‐free conditions. ROP of lactones mediated by the bisurea/7‐methyl‐1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene (MTBD) catalyst exhibits a living/controlled manner, affording the polymers and copolymers with the well‐defined structure, predictable molecular weight, narrow molecular weight distribution, and high selectivity for monomer at low catalyst loadings at ambient temperature. The possible mechanism of bisurea/MTBD‐catalyzed ROP of lactones is proposed, in which the bisurea activates the carbonyl group of lactones while MTBD facilitates the nucleophilic attack of the initiating/propagating alcohol by hydrogen bonding. Moreover, the poly(ε‐caprolactone‐co‐δ‐valerolactone) [P(CL‐co‐VL)] random copolymers with various compositions were synthesized using the bisurea/MTBD catalyst. The measurements of thermal properties and crystalline structure demonstrate that the CL and VL units are cocrystallized in the crystalline phase of P(CL‐co‐VL) copolymers. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 90–100

Glycerol-modified poly(ε-caprolactone): an biocatalytic approach to improve the hydrophilicity of poly(ε-caprolactone)

Novel poly(e-caprolactone) (PCL)–glycerol polyester was synthesized in one step in the presence of Novozym 435 under mild reaction conditions. The objective of the study was to investigate the feasibility of enhancing the hydrophilicity of PCL by condensing it with glycerol through biocatalytic approach. Effect of reaction time, glycerol-to-CL ratio and CL-to-toluene ratio was studied. The 1H NMR and GPC results established that self-condensation of CL units and condensation of CL with glycerol units take place simultaneously. When the glycerol content was 10 and 20 mol% with regard to CL, condensation continued for 6 h; further extension of reaction time resulted in the cleavage of ester linkages. When the glycerol content was increased to 40 mol%, the condensation of CL–glycerol units was accomplished in 4 h; however, the reaction had to get extended beyond 6 h for complete condensation of CL–CL units. The study revealed that the crystallinity and the melting temperature (Tm) of the products altered with an increase in the glycerol content. Furthermore, TGA and contact angle values of water on PCL and its glycerol derivative films revealed that the water uptake capacity of PCL too increased significantly with the increase in glycerol content, rendering PCL more hydrophilic.

Isolation and Reactivity of a Chlorogermyliumylidene Featuring Two Ge–Cl Units

Deprotonation of 1‐mesityl‐4,5‐diphenyl‐2‐imidazole 1 with nBuLi, followed by salt metathesis reaction with GeCl2·dioxane complex, led to the formation of the chlorogermyliumylidene 2 bearing two Ge–Cl units, which has been isolated and fully characterized by standard spectroscopic and X‐ray diffraction analysis. Structural and NMR spectroscopic data as well as computational studies revealed that the positive charge mainly resides on the Ge atom between two nitrogen atoms. Reduction of 2 with an excess amount of lithium metal resulted in Ge–Ge bond formation concomitant with elimination of one of the Ge atoms of 2, to give rise to the digermylenedilithium compound 3 involving intramolecular coordination of the imines and the lone pairs to the Li atoms.

Blocky poly(ɛ‐caprolactone‐co‐butylene 2,5‐furandicarboxylate) copolyesters via enzymatic ring opening polymerization

ABSTRACTCyclic oligo(butylene 2,5‐furandicarboxylate) and ɛ‐caprolactone were copolymerized in bulk at 130–150 °C by enzymatic ring opening polymerization using CALB as catalyst. Copolyesters within a wide range of compositions were thus synthesized with weight‐average molecular weights between 20,000 and 50,000, the highest values being obtained for equimolar or nearly equimolar contents in the two components. The copolyesters consisted of a blocky distribution of the ɛ‐oxycaproate (CL) and butylene furanoate (BF) units that could be further randomized by heating treatment. The thermal stability of these copolyesters was comparable to those of the parent homopolyesters (PBF and PCL), and they all showed crystallinity in more or less degree depending on composition. Their melting and glass‐transition temperatures were ranging between those of PBF and PCL with values increasing almost linearly with the content in BF units. The ability of these copolyesters for crystallizing from the melt was evaluated by comparative isothermal crystallization and found to be favored by the presence of flexible ɛ‐oxycaproate blocks. These copolyesters are essentially insensitive to hydrolysis in neutral aqueous medium but they became noticeably degraded by lipases in an extend that increased with the content in CL units. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 290–299

Dilithium and Magnesium Alkanediides and 1‐Oxaalkanediides

Dilithium and magnesium alkanediides of the types Li(CH2)nLi and [Mg(CH2)n]x represent substance classes with a long tradition, however, the interest in these compounds ceased in recent years. Numerous reasons account for the vanishing attention such as challenging synthetic procedures, poor to moderate yields, complex structures in solution and the solid state, and complex equilibria in solution. Degradation processes (ether degradation, β‐hydride elimination, indirect reduction reactions) increase the intricacy of these compounds because these degradation products take part in the solution equilibria. Thus, chloride and hydride ions are able to act as templates for lithium cages yielding e.g. [(Et2O)4Li]+ [Li12(C4H8)6(@‐X)]– (X = H, Cl) with an X‐centered Li12 icosahedron. Despite these challenges, the dilithium and magnesium alkanediides are a fascinating substance class with a rich chemistry by its own (such as Schlenk‐type equilibria) and as metalating and reducing reagents. The enormous sensitivity toward moisture (hydrolysis reactions) and air (oxidation processes) and reactivity toward ethereal media (ether degradation reactions) also interferes with the dianionic alkanes because alkoxide and oxide ions are strong Lewis bases and as such, are easily integrated in the structures as bridging anions or centers of metal cages. Thus, aerial oxidation leads to insertion of an oxygen atom into the metal–carbon bond yielding 1‐oxaalkanediides. Alternatively, magnesium 1‐oxaalkanediides can be prepared by a two‐step protocol from chloroalkanol, starting with deprotonation of the alcohol functionality with a Grignard reagent and a subsequent reduction of the C–Cl unit with magnesium turnings. This protocol leads to compounds of the type [{MgO(CH2)n}x(MgCl2)y] with additional ether bases saturating the coordination spheres of the magnesium atoms. All these reactions (increasing degradation processes and reactions with inadvertently introduced traces of oxygen and moisture) limit the durability of such solutions, subsumed as aging of these dilithium and magnesium dialkanediide stock solutions, which lead to a changing (decreasing) reactivity of such reagents.

Piperazine-functionalized C60 and diiodine or iodine monochloride as components in forming supramolecular assemblies.

The reaction of the piperazine mono-adduct, N(CH2CH2)2NC60, with diiodine produced well ordered, black crystals of (I2N(CH2CH2)2NI2)C60·2.884(C6H6)·0.116I2, which contains two nearly linear N-I-I units. Reaction of N(CH2CH2)2NC60 with iodine monochloride produced two materials: the dihalogen adduct, (ClIN(CH2CH2)2NICl)C60·2.3(CS2)·0.7(CH2Cl2), when crystallization occurred rapidly from carbon disulfide/dichloromethane solution or the salt, [(N(CH2CH2)2NH)C60+][ICl2-]·CS2, when crystallization happened more slowly from toluene/dichloromethane solution where hydrolysis of the iodine monochloride by adventitious water presumably occurred.

A coordinatively flexible hexadentate ligand gives structurally isomeric complexes M2(L)X3 (M = Cu, Zn; X = Br, Cl).

Polypyridyl multidentate ligands based on ethylenediamine backbones are important metal-binding agents with applications in biomimetics and homogeneous catalysis. The seemingly hexadentate tpena ligand [systematic name: N,N,N'-tris(pyridin-2-ylmethyl)ethylenediamine-N'-acetate] reacts with zinc chloride and zinc bromide to form trichlorido[μ-N,N,N'-tris(pyridin-2-ylmethyl)ethylenediamine-N'-acetato]dizinc(II), [Zn2(C22H24N5O2)Cl3], and tribromido[μ-N,N,N'-tris(pyridin-2-ylmethyl)ethylenediamine-N'-acetato]dizinc(II), [Zn2Br3(C22H24N5O2)]. One Zn(II) ion shows the anticipated N5O coordination in an irregular six-coordinate site and is linked by an anti carboxylate bridge to a tetrahedral ZnX3 (X = Cl or Br) unit. In contrast, the Cu(II) ions in aquatribromido[μ-N,N,N'-tris(pyridin-2-ylmethyl)ethylenediamine-N'-acetato]dicopper(II)-tribromido[μ-N,N,N'-tris(pyridin-2-ylmethyl)ethylenediamine-N'-acetato]dicopper(II)-water (1/1/6.5) [Cu2Br3(C22H24N5O2)][Cu2Br3(C22H24N5O2)(H2O)]·6.5H2O, occupy two tpena-chelated sites, one a trigonal bipyramidal N3Cl2 site and the other a square-planar N2OCl site. In all three cases, electrospray ionization mass spectra were dominated by a misleading ion assignable to [M(tpena)](+) (M = Zn(2+) and Cu(2+)).

Biodegradable Copolymers Obtained by Solution Polymerization

This study aims the synthesis of copolymers of poly (l-lactic acid) and polycaprolactone by ring opening polymerization. The reactions between l-lactide (LLA) and ε-caprolactone (CL) monomers, in 100/0, 95/5, 90/10 and 80/20 LLA/CL mass ratios, were conducted in refluxing toluene, using Stannous octoate as iniciator, methanol as co-iniciator and inert atmosphere (N2). The reaction medium was maintained under stirring at 120 °C for 24 hours. The samples were characterized by carbon-13 and proton nuclear magnetic resonance (C13-NMR and H1-NMR), and gel permeation chromatography (GPC). Monomers were characterized by thermogravimetry (TG). Copolymers were formed only in samples containing 20 wt% ε-caprolactone. NMR spectra of the other samples showed no evidence of CL units. This fact may be associated with the low-temperature volatilization of monomers. The GPC analysis showed that the increase of CL concentration decrease the molecular weight of copolymers.

Elucidating Lewis acidity of metal sites in MFU-4l metal-organic frameworks: N2O and CO2 adsorption in MFU-4l, CuI-MFU-4l and Li-MFU-4l

The interaction strength of N2O and CO2 molecules with different Lewis-acidic sites within MFU-4l–type metal-organic frameworks was studied via gas sorption measurements and density-functional theory calculations. MFU-4l comprising Zn–Cl units shows only physisorption of both gases. Introduction of Li into the parent MFU-4l framework leads to a remarkable increase of binding strength of both N2O and CO2 showing considerable Lewis acidity of LiI centers. CuI-MFU-4l shows even stronger binding of N2O, as compared to Li-MFU-4l, whereas CO2 doesn't bind to CuI centers. Preferential binding of N2O to CuI centers was also confirmed by in situ synchrotron X-ray powder diffraction measurements. These results show that CuI-MFU-4l can be considered as a material for selective N2O adsorption.

Substituted corannulenes and sumanenes as fullerene receptors. A dispersion-corrected density functional theory study.

Stacking interactions between substituted buckybowls (corannulene and sumanene) with fullerenes (C60 and C70) were studied at the B97-D2/TZVP level of theory. Corannulene and sumanene monomers were substituted with five and six Br, Cl, CH3, C2H, or CN units, respectively. A comprehensive study was conducted, analyzing the interaction of corannulenes and sumanenes with several faces of both fullerenes. According to our results, in all cases substitution gave rise to larger interaction energies if compared with those of unsubstituted buckybowls. The increase of dispersion seems to be the main source of the enhanced binding, so an excellent correlation between the increase of interaction energy and the increase of dispersion contribution takes place. One of the noteworthy phenomena that appears is the so-called CH···π interaction, which is responsible for the strong interaction of sumanene complexes (if compared with that of corannulene complexes). This interaction also causes the substitution with CH3 groups (in which one of the H atoms points directly to the π cloud of fullerene) to be the most favorable case. This fact can be easily visualized by noncovalent interaction plots.

Synthesis of 6‐O‐Poly(ϵ‐caprolactone)‐L‐ascorbic Acid and its Controlled Release from Supramolecular Polymer Micelles

Lipophilic 6-O-poly (ϵ-caprolactone)-L-ascorbic acid (AA-6-PCL) is synthesized through ROP of ϵ-caprolactone (CL). The number of repeating CL units in the polymer chain varies from 6 to 19. AA-6-PCL loaded supramolecular polymer micelles (SMPMs) are constructed with β-cyclodextrin (β-CD) and PCL as blocks. Transmission electron microscopy images show a nanospheric morphology of the micelles with a size range of 43.3 ± 5.0 nm. The drug loading contents are 22.53-39.23% for AA-6-PCL. AA-6-PCL exhibits high radical scavenging capacity (93.96-96.73%) and efficient scavenging potency, and a cytotoxicity study proves the excellent cytocompatibility of AA-6-PCL loaded β-CD/PCL SMPMs, which altogether herald their potential application in the study of the induced pluripotent stem cells.

Coordination of N,N-Chelated Re(CO)3Cl Units Across a Mo2 Quadruple Bond: Synthesis, Characterization, and Photophysical Properties of a Re–Mo2–Re Triad and Its Component Pieces

2-(2-Pyridyl)-4-methylthiazole carboxylic acid (PMT-H) and rhenium tricarbonyl chloride react to form the red crystalline compound fac-Re(PMT-H)(CO)3Cl, I, which is an analog of the well-known Re(bpy)(CO)3Cl molecule, where bpy is 2,2'-bipyridine. The acids PMT-H (2 equiv) and Re(PMT-H)(CO)3Cl (2 equiv) also react with Mo2(T(i)PB)4 (T(i)PB = 2,4,6-triisopropylbenzoate) in toluene to give the red compound trans-Mo2(T(i)PB)2(PMT)2, II, and the royal blue compound trans-Mo2(T(i)PB)2[(PMT)Re(CO)3Cl]2, III, respectively. The X-ray and spectroscopic characterization of I confirms its close relationship with Re(bpy)(CO)3Cl, as does the spectroscopic characterization of compounds II and III as analogs of other compounds of the form trans-M2(TiPB)2L2, where L is a π-acceptor ligand. Electronic structure calculations on model compounds II' and III', where formate ligands substitute for T(i)PB, show that the highest occupied molecular orbital (HOMO) in II is Mo2δ. When the Re(CO)3Cl unit is attached to the PMT ligand to form III, this orbital is stabilized significantly and now becomes associated with a close in energy band of Re d(6), t2g type orbitals. Oxidation of III is shown to be Mo2-based, as evident by EPR spectroscopy, and the lowest-energy electronic absorption corresponds to a Mo2δ-to-PMT π* transition. The S1 states in both II and III are metal-to-ligand charge-transfer (MLCT), and the lowest-energy triplet sate, T1 is (3)MoMoδδ*, as evidenced by its steady state emission spectral features. The excited states of compounds I (T1) and III (S1 and T1) have been investigated by time-resolved infrared spectroscopy (TRIR). The spectral features of I parallel those for Re(bpy)(CO)3Cl, with the lowest-energy T1 state corresponding to Re dπ to PMT-H π* charge transfer, producing higher-energy CO stretching vibrations relative to the ground state. For III, the CO vibrations are shifted to lower energy, consistent with charge being located on the PMT ligand, which enhances Re-to-CO backbonding. In the MoMoδδ* T1 state, however, the backbonding is reduced to the PMT ligand, and the CO stretches are at slightly higher energy relative to the ground state.

Trans-Dichloridobis(quinoline-κN)platinum(II)

In the title complex, trans-[PtCl2(C9H7N)2], the PtII ion is four-coordinated in an essentially square-planar coordination environment defined by two N atoms from two quinoline (qu) ligands and two Cl− anions. The Pt atom is located on an inversion centre and thus the asymmetric unit contains one half of the complex; the PtN2Cl2 unit is exactly planar. The dihedral angle between the PtN2Cl2 unit and the quinoline ligand is 85.1 (1)°. In the crystal, the complex mol­ecules are stacked into columns along the b axis. In the columns, several inter­molecular π–π inter­actions between the six-membered rings are present, the shortest ring centroid–centroid distance being 3.733 (5) Å between pyridine rings.

Synthesis, structure and properties of poly(L-lactide-co-[formula omitted]-caprolactone) statistical copolymers

Four poly(L-lactide-co-ε-caprolactone) (PLCL) copolymers were synthesized at 120, 130, 140 and 150 °C by ring opening polymerization using stannous octoate catalyst at a 2000:1 comonomer:catalyst ratio. Gel permeation chromatography (GPC) and 1H NMR measurements were performed to determine the molecular weight, composition and chain microstructure of copolymers of L-lactide(LA):ε-caprolactone(CL) synthesized using 90:10, 80:20, 75:25 and 70:30 feed ratios. The overall conversion of these PLCL copolymers was in the range of 80%–90% leading to weight average molecular weights (Mw) between 98,500 and 226,000 g mol−1 depending on feed composition and polymerization temperature. At temperatures lower than 140 °C, the incorporation of CL units into polymer chains was incomplete because of the low reactivity of CL, thus at 120 °C the copolymer composition was difficult to control obtaining more LA in the copolymer than the desired, hence the blocky character of PLCL copolymers also increased. At 150 °C the catalyst was less effective and the molecular weights of the copolymers took lower values. A temperature of 140 °C was established as optimal to obtain highest yields and molecular weight. The number average crystallizable lactide sequence lengths (lLA) shifted from 6.5 to 16.7 LA repeat units for PLCL polymerized at 140 °C while the randomness character (R) value shifted from 0.4 for polymerization at 130 °C to 0.6, at 150 °C. Increasing the LA content in the copolymers the glass transition temperature and the crystallizability and melting temperature of PLCLs approached to that of PLLA homopolymer. The aging sensitivity of PLCLs increased with CL content. A double Tg behavior due to phase separation associated to crystallizing LA blocks was observed during aging. The mechanical properties, however, evolved toward the PLLA character when the molar content of LA in PLCL was increased from 66% to 90%, observing a shift from an elastomeric thermoplastic behavior to that of a glassy plastic, reflected by an increase in tensile modulus (from 12.0 to 1343.1 MPa) and a decrease in strain recovery after break (from 93.5% to 25.0%). Small amounts of CL content in the copolymers produced large improvements in their deformability with regard to PLLA. In addition, thermogravimetric analysis demonstrated that PLCLs are more stable to thermal degradation than PLLA and they undergo a more complex degradation mechanism than those of the corresponding homopolymers.

Catena-Poly[[(8-aminoquinoline-κ2N,N′)cadmium]-di-μ-thiocyanato-κ2N:S;κ2S:N-[(8-aminoquinoline-κ2N,N′)cadmium]-di-μ-chlorido

In the title compound, [CdCl(NCS)(C9H8N2)]n, the CdII atom is in a distorted octa­hedral coordination environment defined by two chloride anions, two N atoms from an 8-amino­quinoline ligand, one N atom from one thio­cyanate anion and one S atom from a symmetry-related thio­cyanate anion. Two CdII atoms are bridged by two chloride anions, forming an inversion-related Cd2Cl2 unit; these units are further linked through thio­cyanate anions, leading to a chain structure extending parallel to [010]. Weak π–π stacking inter­actions with centroid–centroid distances of 3.430 (4) Å and an inter­planar separation of 3.390 (3) Å between the pyridine and benzene rings link the chains into a two-dimensional network parallel to (10). Weak inter­molecular C—H⋯Cl hydrogen-bonding inter­actions help to consolidate the crystal packing.

ε-Caprolactone-Based Macromonomers Suitable for Biodegradable Nanoparticles Synthesis through Free Radical Polymerization

New ε-caprolactone (CL)-based materials were synthesized. Bulk ring-opening polymerization of ε-caprolactone with 2-hydroxyethyl methacrylate (HEMA) as cocatalyst was carried out to produce various macromonomers composed of HEMA functionalized with 1–10 CL units. All of the HEMA-CL macromonomers have been characterized by size exclusion chromatography (SEC) and 1H NMR. For SEC analysis universal calibration was applied, and Mark–Houwink parameters for poly(HEMA-g-CL3) were obtained. Macromonomers with different CL chain length were polymerized through free radical polymerization, in both batch and semibatch emulsion polymerization to produce CL-based nanoparticles (NPs) with narrow particle size distribution. Various reactions parameters were investigated, namely the type of the emulsifier, the feeding conditions, and the macromonomer chain length. Finally, a simple and qualitative degradation study of selected samples was carried out in order to verify the degradability of these CL-based NPs.