Vinyl End Groups Research Articles

Experimental and modeling study of the solid state polymerization of poly(ethylene terephthalate) over a wide range of temperatures and particle sizes

AbstractThe solid state polymerization (SSP) of poly(ethylene terephthalate) was studied experimentally over a wide range of pellet sizes and temperatures. A comprehensive model was developed. It considered polycondensation, degradation and polycondensation of vinyl end groups together with diffusion. The reaction rate constants, diffusivities and the corresponding activation energies were obtained through parameter identification using experimental data. The effects of the reaction temperature and pellet size on the SSP time were also investigated. A decrease in the particle size decreases the concentration of the vinyl end groups and narrows the concentration distribution of end groups inside poly(ethylene terephthalate) particles. A decrease in the size of pellets also favors diffusion. Nevertheless it is preferable that the size of pellets be between 1 and 2 mm because too small pellets bring about difficulties with preparation and handling. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Synthesis and characterization of the core–shell magnetic molecularly imprinted polymers (Fe3O4@MIPs) adsorbents for effective extraction and determination of sulfonamides in the poultry feed

In this study, we present a general method to prepare the core–shell magnetic molecularly imprinted polymers (MIPs) nanoparticles (NPs) for sulfamethazine (SMZ). The resulting Fe3O4@MIPs NPs possess a highly improved imprinting effect, fast adsorption kinetics and high adsorption capacity, and can be applied to extract sulfonamide in the poultry feed. In this protocol, the magnetite NPs were synthesized by co-precipitating Fe2+ and Fe3+ in an ammonia solution first. Silica was then coated on the Fe3O4 NPs using a sol–gel method to obtain silica shell magnetic NPs. Subsequently, the vinyl groups were grated onto silica-modified Fe3O4 surface by 3-methacryloyloxypropyltrimethoxysilane. Finally, the MIPs films were formed on the surface of Fe3O4@SiO2 by the copolymerization of vinyl end groups with functional monomer, methacrylic acid, cross-linking agent, ethylene glycol dimethacrylate, the initiator azo-bis-isobutyronitrile and template molecule, sulfamethazine. The morphology, magnetic, adsorption and recognition properties of Fe3O4@MIPs NPs were characterized using transmission electron microscope (TEM), scanning electron microscope (SEM), Fourier transform infrared (FT-IR) spectrometer, vibrating sample magnetometer (VSM) and re-binding experiments. The results showed that the binding sites of Fe3O4@MIPs were good accessibility, fast adsorption rate and the maximum adsorption capacity of Fe3O4@MIPs to SMZ was 344.8μgg−1. The selectivity of the obtained Fe3O4@MIPs NPs were elucidated by the different rebinding capability of SMZ and structural related sulfonamides in the mixed solution. The results indicated that the Fe3O4@MIPs had high imprinting factor 9.5 and significant selectivity. A method was developed for enrichment and determination of SMZ in the poultry feed samples with recoveries of duck and chicken feed ranging from 63.3 to 76.5% and 68.7 to 74.7%, respectively and the relative standard deviations (RSD) (<6.7%).

Rational design of core–shell molecularly imprinted polymer based on computational simulation and Doehlert experimental optimization: application to the separation of tanshinone IIA from Salvia miltiorrhiza Bunge

Computational simulation and Doehlert experimental optimization were done for the rational design of a core-shell molecularly imprinted polymer (CS-MIP) for use in the highly selective separation of Tanshinone IIA (TSIIA) from the crude extracts of Salvia miltiorrhiza Bunge (SMB). The functional monomer layer of the polymer shells directed the selective occurrence of imprinting polymerization at the surface of silica through the copolymerization of vinyl end groups with functional monomers and also drove TSIIA templates into the formed polymer shells through the charge-transfer complex interactions between TSIIA and the functional monomer layer. As a result, the maximum rebinding capacity was achieved with the use of optimal grafting ratio by the Doehlert design. The CS-MIP exhibited high recognition selectivity and binding affinity to TSIIA. When the imprinted particles were used as dispersive solid phase extraction sorbents, the recovery yield of TSIIA reached 93% by a one-step extraction from the crude extracts of SMB, and the purity of TSIIA was larger than 98% by HPLC analysis. These results show the possibility of a highly selective separation and enrichment of TSIIA from the SMB using the TSIIA-imprinted core-shell molecularly imprinted polymers.

Phosphonium bis(glycolates) and phosphinoglycolates: Synthesis, solvolysis, oxidation to (thio)phosphinoylglycolates and use as ligands in Ni-catalyzed ethylene oligomerization

Secondary phosphines, glyoxylic acid hydrate and amines react to form organoammonium phosphonium bis(glycolates) 1a–d. In CD3OD solution, diphenylphosphonium bis(glycolates) undergo reversible solvolysis to phosphinoglycolates 2a,b and acetalic glyoxylic species. The P-dialkyl species 1c avoids this and maintains the phosphonium bis(glycolate) structure in CD3OD (cHex2P) or undergoes further solvolysis with partial formation of R2PH (R=tBu). Condensation to phosphinoglycines, e.g. 3b, observed for primary amines, does not take place with N-secondary amines at room temperature. Heating leads to condensation but is followed by decarboxylation as shown for the conversion of 2a to 4a. Because of the kinetic lability, the phosphonium compounds 1a–d are sensitive to oxidation by air, H2O2, or sulfur. The resulting phosphinoyl and thiophosphinoyl glycolates and glycolic acids 5–8 are kinetically stable. Precatalyst solutions formed from 1a, c, d and Ni(COD)2 in THF developed moderate to good activity in the oligo- or polymerization of ethylene to linear products containing methyl and vinyl end groups. Activity and molecular weights increased with the +I-effect of the P-substitutents. The solution structures of the novel compounds were elucidated by multinuclear NMR spectroscopy. For 7a a crystal structure analysis is also presented.

전자빔을 이용한 폴록사머 하이드로젤의 제조 및 구강 점막부착성 약물전달을 위한 특성 분석

In this study, poloxamer hydrogels were prepared by electron beam irradiation and evaluated for potential application as a buccal mucoadhesive drug delivery system. Poloxamer, one of typical thermoresponsive polymers, was modified to have vinyl end groups for crosslinking reaction, and its hydrogels were fabricated by irradiation crosslinking reaction. Carbopol as a mucoadhesive polymeric additive was introduced to improve the mucoadhesive property of the hydrogels and its effect on the mucoadhesion and drug release properties was investigated. The results showed that the end group modification of poloxamer and the addition of carbopol improved mucoadhesive force and mechanical properties and led to a sustained drug release behavior.

Super-tough double-network hydrogels reinforced by covalently compositing with silica-nanoparticles

We have successfully developed hydrogels with high compressive toughness by reinforcing the double-network structure (PAMPS/PAAm) with grafted silica nanoparticles. Silica nanoparticles grafted with vinyl end groups were used as macro-crosslinkers to copolymerize with AMPS, yielding a nanocomposite first network. Subsequent introduction of a secondary PAAm network resulted in super-tough double-network (DN) composite hydrogels, which do not fracture upon loading up to 73 MPa and a strain above 0.98. The compressive strength, swelling behavior, and morphology of the silica-grafted DN hydrogels were investigated as functions of nanoparticle content and particle size, in comparison with silica nanoparticle-filled DN gels without covalent bonding to the polymer network. Maximal reinforcement of the DN gels was achieved at around 1 wt% (weight percent) of grafted silica nanoparticles with respect to AMPS. Unique embedded micro-network structures were observed in the silica-grafted DN gels and accounted for the substantial improvement in compressive toughness. The fracture mechanism is discussed in detail based on the yielding behavior of these covalently composited hydrogels.

Effect of TiO2 nanoparticle surface functionalization on protein adsorption, cellular uptake and cytotoxicity: the attachment of PEG comb polymers using catalytic chain transfer and thiol–ene chemistry

A successful modification of titanium dioxide (TiO2) nanoparticles surfaces by a grafting-to polymer technique combining catalytic chain transfer and thiol–ene click chemistry is reported. Vinylic end functional polymers were first prepared by catalytic chain transfer polymerization (CCTP) using oligo(ethylene glycol) methacrylate as a monomer. The presence of vinylic end groups was then exploited to attach the polymers to thiol functionalized TiO2 nanoparticles via thiol–ene Michael nucleophilic reactions. X-ray photoelectron spectroscopy (XPS), attenuated total reflectance-infrared (ATR-IR), dynamic light scattering (DLS), and thermogravimetric analyses (TGA) were used to verify the successful modification of the TiO2 surface. The modified TiO2 nanoparticles were stable in cell culture media and formed smaller aggregates when compared to non-surface modified nanoparticles. Cellular toxicity of the hybrid TiO2–polymer particles towards human lung cell lines A549 and H1299 in vitro was evaluated. Results from one-dimensional gel electrophoresis show the presence of polymer layers around the particles affects the adsorption of protein onto the TiO2 surface. The reduction in particle aggregate size and changes to the particle surface chemistry, following polymer grafting, was found to reduce cellular uptake and diminish cytotoxicity for both human lung cell lines tested.

Synthesis of Monodisersed PSt-g-PNIPAAm Nanospheres by UV Initiated Dispersion Polymerization

Ultraviolet(UV) irradiated polymerization is a new way to synthesis of the polymeric nanoparticles due to its security, environmental protection, and low investment, as compared to the thermal-initiated polymerization. In this paper, polystyrene-g- poly(N-isopropylacrylamide) (P(St-g-NIPAAM)) nanospheres were prepared by photo-initiated dispersion copolymerization of St and macromonomers, PNIPAAM with a vinyl end group, in a mixture of ethanol and water using 2,2-dimethoxy-2-phenylacetophenone (BDK) as the photo-initiator. The obtained nanospheres were characterized by scanning electron microscopy (SEM) and laser light scattering (LLS). The results showed that the P(St-g-NIPAAM) particles were highly spherical and monodisperse. The size of the nanospheres could be controlled by changing the concentration of the macromonomers, polymerization temperature, and irradiation time and energy.

Multiobjective Optimization of Industrial Processes Using Elitist Multiobjective Differential Evolution (Elitist-MODE)

Multiobjective optimization (MOO) refers to solving more than one-objective optimization problems simultaneously to attain a set of solutions, i.e., the Pareto front. In this study, an elitist strategy of multiobjective differential evolution (Elitist-MODE) algorithm is used to find the Pareto optimal solutions for a set of multiobjective test problems [POL (unconstrained), CONSTR-EX (constrained), and TNK (constrained)] and two-industrial engineering process problems, namely, styrene reactor and polyethylene terephthalate reactor (PET). A detailed analysis is reported for the test problems and real-world industrial problems, and the obtained Pareto fronts are compared with the Pareto front obtained using MODE and MODE III algorithms. Simultaneous maximization of selectivity and yield (for the styrene reactor) and simultaneous minimization of acid- and vinyl-end group concentrations (for the PET reactor) are considered. A detailed analysis of obtained Pareto fronts with respect to the set of decision variables for the individual industrial study is reported. It is observed that the improved strategies of MODE algorithms in general converge to the true Pareto front both for the test problems (constrained/unconstrained) and complex industrial problems. It is also suitable for solving the problems having disconnected Pareto front.

Synthesis of hybrid dendritic molecules with diazaphospholidine oxide grafted at the surface of octavinylsilsesquioxane (OVS)

A range of dendritic molecules was made using the monodentate SEMI-ESPHOS phosphine oxide ligand, which was derivatised with a series of functional groups including bromide, vinyl, allyl and terminal alkyne. Several methods to attach the resulting precursors onto octavinylsilsesquioxane (OVS), ranging from hydrosilylation, Suzuki, Heck, Grubbs or Sonogashira coupling reactions, have been investigated. Cross-metathesis of SEMI-ESPHOS oxide dendrons containing vinyl end groups with OVS catalyzed by Grubbs' catalyst was proven to be effective in the formation of precursors for dendritic molecules based on OVS.

Synthesis and modification of thermoresponsive poly(oligo(ethylene glycol) methacrylate) via catalytic chain transfer polymerization and thiol–ene Michael addition

Various poly(oligo(ethylene glycol) methyl ether methacrylate)s (POEGMEMAs) have been prepared by Catalytic Chain Transfer Polymerization (CCTP) using a range of OEGMEMA monomers (molecular weight from 180 to 1100 g mol−1). The chain transfer constants of bis(boron difluorodimethylglyoximate) cobalt(II) (CoBF) were determined and are reported for each monomer. The copolymerization of POEGMEMA (Mn = 475 g mol−1) with diethylene glycol methyl ether methacrylate (DEGMEMA) yielded thermoresponsive polymers. The lower critical solution temperatures (LCSTs) of the polymer chains can be tuned by the copolymer composition over the range 30 °C to 95 °C. In addition, the presence of the vinylic end-group, characteristic of CCT polymerization, provided further scope for post-synthetic modification via thiol–ene click chemistry, through nucleophilic Michael addition with various functional thiol compounds such as 2-mercaptoethanol, 3-mercaptopropionic acid, benzyl mercaptan and 1-dodecanethiol. The thiol–ene reaction was rigorously tested, optimized and characterized in this study in terms of solvents and most importantly the choice of the catalyst: dimethyl phenyl phosphine, tertiary amine or hexylamine. The optimum conditions reported allow near-quantitative functionalization of these macromonomers without significant side reactions. The effect of the end-group on the LCST has also been investigated, as well as thermal stability temperature of the copolymers.

Long-chain branching in PE from Cr/aluminophosphate catalysts

Phillips Cr/silica catalysts have long been known to produce long-chain branching (LCB) in polyethylene (PE) through macromer incorporation. In fact, the manipulation of LCB levels through catalyst variables is a very useful way of controlling properties and molding behavior in commercial PE resins. Using alumina as the support, instead of silica, is one way of achieving very low levels of LCB. Adding small amounts of phosphate to the alumina base as a modifier causes a large rise in LCB levels. Phosphate also promotes the activity and melt index potential of the catalyst by contributing a large new low-MW population of PE chains. In this study LCB levels were measured and found to correlate nicely with the amount of phosphate added. The polymer from such a catalyst was then solvent-fractionated to determine the location of the LCB. It was found to be concentrated in this same low-MW polymer, to which the phosphate contributes, which suggests that the phosphate-associated Cr sites have a tendency to produce LCB. However, the incorporation of 1-hexene resulted in a flat short-chain branch (SCB) profile, indicating that there was no parallel behavior among the different sites between SCB and LCB incorporation. These results indicate a slightly different mechanistic pathway between the two monomers (macromer and 1-hexene). Furthermore the Cr sites must have incorporated macromers that were produced only at the same site, and not (as is usually portrayed) randomly from a general pool of vinyls contributed by all sites. To explain this finding, alternatives to the widely accepted random-incorporation mechanism are proposed, including a “tethered” vinyl end-group, and intra-, rather than the traditional inter-, molecular insertion of macromer.

Novel thermosets based on DGEBA and hyperbranched polymers modified with vinyl and epoxy end groups

The cationic polymerization of DGEBA with two hyperbranched polymers (HBPs) with epoxy or vinyl end groups, using ytterbium triflate as initiator, has been studied. These HBPs have been obtained from commercial Boltorn H30 of which terminal hydroxyl groups have been replaced with long aliphatic ester chains having vinyl or epoxy end groups. Differences between the HBPs added as modifiers are observed with respect to the curing kinetics, network development, properties and morphology of the cured materials. While terminal epoxy groups ease the solubility of the HBP in DGEBA and allows its covalent incorporation into the network structure, the HBP with vinyl terminal groups is only miscible at high temperature and phase-separates during curing. As a consequence, morphology and thermal–mechanical properties are strongly dependent on the HBP employed.

Selective extraction of sulfonamides from food by use of silica-coated molecularly imprinted polymer nanospheres

We report the use of nanospheres prepared by coating silica with molecularly imprinted polymer (MIP) for sulfamethoxazole (SMO). The resulting SiO(2)-SMO-MIP nanoparticles have highly improved imprinting and adsorption capacity, and can be used for separation and determination of sulfonamides in eggs and milk. In the synthesis, monodispersed SiO(2) nanoparticles (Si-NP) of diameter 80 nm were amino-modified by reaction with 3-aminopropyltriethoxylsilane. The acryloyl monolayer was then grafted onto the amine-modified Si-NP. Finally, the MIP films were coated on to the surface of Si-NP by the copolymerization of the vinyl end groups with functional monomer (acrylamide), cross-linking agent (ethylene glycol dimethacrylate), initiator (azo-bis-isobutyronitrile), and template molecule (sulfamethoxazole). The resulting SiO(2)-SMO-MIP-NP were characterized by transmission electron microscopy, scanning electron microscopy, and Fourier transform infrared spectrometry. The adsorption properties were demonstrated by equilibrium rebinding experiments and Scatchard analysis. The results showed that the binding sites of the SiO(2)-SMO-MIP were highly accessible, and the maximum adsorption capacity of the SiO(2)-SMO-MIP for SMO was 20.21 mg g(-1). The selectivity of the SiO(2)-SMO-MIP-NP obtained was elucidated by using SMO and structurally related sulfonamides. The results indicated that the SiO(2)-SMO-MIP had significant selectivity for SMO. The feasibility of removing SMO and sulfadiazine (SDZ) from food samples was proved by use of spiked milk and eggs. A method for the separation and determination of trace SMO and SDZ in milk and egg samples was developed, with recoveries ranging from 69.8% to 89.1%.

Mechanistic studies on the photodegradation of 2,5-dialkyloxyl-substituted para-phenylenevinylene oligomers by singlet oxygen

Time-dependent UV/visible absorption changes are observed on photolysis of aerated solutions of monodisperse, vinyl end-capped 2,5-diheptyloxyl substituted PV-oligomers (OPV, n = 1, 2, 3). In all cases, photolysis occurs in at least two distinct stages. Evidence for the intermediacy of singlet oxygen comes from pulse radiolysis and time-resolved luminescence studies, which confirm formation of the OPV triplet state and its quenching by molecular oxygen to produce singlet oxygen. The subsequent reaction with oligomers is observed directly by time-resolved phosphorescence and indirectly through product identification. The results strongly suggest that the reaction between singlet oxygen and OPV proceeds via cycloaddition, leading to bond scission and aldehyde group formation. The reactivity of vinylene linkages is greater than of vinyl end groups. Consequently, the photostability decreases as the chain length is extended. Implications on the oxidative degradation of poly(p-phenylenevinylene)s in optoelectronic devices, and of competing singlet oxygen and superoxide radical anion degradation pathways, are discussed.

Energy-Dependent Collision-Induced Dissociation of Lithiated Polytetrahydrofuran: Effect of the Size on the Fragmentation Properties

The fragmentation properties of singly and doubly lithiated polytetrahydrofuran (PTHF) were studied using energy-dependent collision-induced dissociation. The product ion spectrum of [PTHF + Li](+) showed the formation of three different series corresponding to product ions with hydroxyl, aldehyde and vinyl end-groups. Interestingly, besides these series, two additional, non-lithiated product ions C(4)H(9)O(+) and C(4)H(7)(+) were identified in the MS/MS spectra. The MS/MS of the doubly lithiated PTHF ([PTHF + 2Li](2+)) with a number of repeat units ranging from 8 to 27 showed the formation of product ions similar to those of the singly lithiated series, however, doubly lithiated product ions and product ions formed by the loss of one Li(+)-ion from the precursor ion also appeared with significant abundances. Analysis of the breakdown curves for the singly and doubly charged PTHF indicated that the series A ions are formed most probably together with the series B ions, while members of the series C ions appeared at significantly higher collision energies. The fragmentation properties of [PTHF + Li](+) and [PTHF + 2Li](2+) were also interpreted using the survival yield method. It was found that the collision energy/voltage necessary to obtain 50% fragmentation (CV(50)) was dependent linearly on the number of the repeat units, i.e., on the size, or the number of degrees of freedom (DOF).

Effect of catalyst composition on chain-end-group of polyethylene produced by salen-type complexes of titanium, zirconium, and vanadium

The chain end structures of polyethylenes produced by salen complexes of titanium, zirconium, and vanadium, activated by MAO or common alkylaluminium compounds were investigated by 1H NMR and FTIR spectroscopy. The polymerization process with the use of vanadium complexes was found to produce polymers with only vinyl end groups in practice. In the processes catalyzed by titanium and zirconium complexes activated by MAO or Et2AlCl, not only β-hydrogen elimination and/or chain transfer to the monomer occurs but also the chain termination reaction takes place in which an organoaluminium cocatalyst is involved. That reaction proceed particularly easily in the systems: titanium complex/Et2AlCl.

Limitations of radical thiol‐ene reactions for polymer–polymer conjugation

AbstractIn this work, we report our findings on the use of radical thiol‐ene chemistry for polymer–polymer conjugation. The manuscript combines the results from the Preparative Macromolecular Chemistry group from the Karlsruhe Institute of Technology (KIT) and the Polymer Chemistry Research group from Ghent University (UGent), which allowed for an investigation over a very broad range of reaction conditions. In particular, thermal and UV initiation methods for the radical thiol‐ene process were compared. In the KIT group, the process was studied as a tool for the synthesis of star polymers by coupling multifunctional thiol core molecules with poly(n‐butyl acrylate) macromonomers (MM), employing thermally decomposing initiators. The product purity and thus reaction efficiency was assessed via electrospray ionization mass spectrometry. Although the reactions with 10 or 5 equivalents of thiol with respect to macromonomer were successful, the coupling reaction with a one‐to‐one ratio of MM to thiol yielded only a fraction of the targeted product, besides a number of side products. A systematic parameter study such as a variation of the concentration and nature of the initiator and the influence of thiol‐to‐ene ratio was carried out. Further experiments with poly(styrene) and poly(isobornyl acrylate) containing a vinylic end group confirmed that thermal thiol‐ene conjugation is far from quantitative in terms of achieving macromolecular star formation. In parallel, the UGent group has been focusing on photo‐initiated thiol‐ene chemistry for the synthesis of functional polymers on one hand and block copolymers consisting of poly(styrene) (PS) and poly(vinyl acetate) (PVAc) on the other hand. Various functionalization reactions showed an overall efficient thiol‐ene process for conjugation reactions of polymers with low molecular weight compounds (∼90% coupling yield). However, while SEC and FT‐IR analysis of the conjugated PS‐PVAc products indicated qualitative evidence for a successful polymer–polymer conjugation, 1H NMR and elemental analysis revealed a low conjugation efficiency of about 23% for a thiol‐to‐ene ratio equal to one. Blank reactions using typical thiol‐ene conditions indicated that bimolecular termination reactions occur as competitive side reactions explaining why a molecular weight increase is observed even though the thiol‐ene reaction was not successful. The extensive study of both research groups indicates that radical thiol‐ene chemistry should not be proposed as a straightforward conjugation tool for polymer–polymer conjugation reactions. Head‐to‐head coupling is a major reaction pathway, which interrupts the propagation cycle of the thiol‐ene process. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1699–1713, 2010

Poly(ethylene glycol)-Based Thiol-ene Hydrogel Coatings−Curing Chemistry, Aqueous Stability, and Potential Marine Antifouling Applications

Photocured thiol-ene hydrogel coatings based on poly(ethylene glycol) (PEG) were investigated for marine antifouling purposes. By varying the PEG length, vinylic end-group, and thiol cross-linker, a library of hydrogel coatings with different structural composition was efficiently accomplished, with or without ester linkages. The thiol-methacrylate and thiol-allyl systems were evaluated with respect to curing, degradation, as well as antifouling properties. Methacrylate-based systems exhibited homopolymerization, whereas allyl-based systems reacted more selectively through thiol-ene couplings reaction. The ester-free hydrogels elucidated higher hydrolytic stability whereas longer PEG chains accelerated the degradation process. The antifouling properties were evaluated by protein adsorption with Bovine serum albumin (BSA) and bioassays with the marine bacteria, Cobetia marina, and the marine diatom, Amphora coffeaeformis; in all tests, longer PEG lengths improved the antifouling properties.

Oligomeric Tectonics: Supramolecular Assembly of Double‐Stranded Oligobisnorbornene through π–π Stacking

Self-assembly at the molecular level in solutions or on a surface is a subject of current interest. Herein we describe the tailoring of oligobisnorbornene 1, which represents an innovative concept of a preorganized building block on the tens of nanometer scale. The rodlike 1 has vinyl and styrenyl end groups. Scanning tunneling microscopy (STM) reveals that the oligomers aggregate anisotropically along the long axis and form a one-dimensional assembly in which, remarkably, no interstitial gap appears between neighboring oligomers. Dynamic light-scattering (DLS) measurements indicate that the assembly develops in solution. With a shear treatment for dropcast films, a unidirectionally ordered domain with a defect density less than 0.5 % can be prepared. Simulation results by molecular dynamics suggest that there may be multiple interactions such as pi-pi stacking and dipolar attractions taking place between the termini of the oligomers. To demonstrate the importance of double bonds in the oligomeric backbones and termini towards the tectonic assembly, a hydrogenated analogue was synthesized; pi-pi interactions are thus less significant and the film morphology is completely different from that of 1. This work extends the concept of molecular tectonics to preorganized oligomers and opens up a new avenue of nanopatterning toward nanodevices.