Charged Terminal Groups Research Articles

Antifreezing, Antidrying, and Conductive Hydrogels for Electronic Skin Applications at Ultralow Temperatures.

Although conductive hydrogel-based flexible electronic devices have superb flexibility and high conductivities, they tend to malfunction in dry or frigid areas. Herein, an ultralow-temperature tolerant, antidrying, and conductive composite hydrogel is designed for electronic skin applications on the basis of the synergy of double-cross-linked polymer networks, Hofmeister effect, and electrostatic interaction and fabricated by in situ free radical polymerization of 2-acrylamido-2-methyl-1-propanesulfonic acid and acrylic acid in the presence of poly(vinyl alcohol) and conductive MXene sheets, followed by impregnation with LiCl. Thanks to the synergy of LiCl and the charged polar terminal groups of the synthesized polymers, the composite hydrogel can not only bear an ultralow temperature of -80 °C without freezing but also maintain its original mass. Meanwhile, the resultant hydrogel possesses satisfactory self-regeneration ability benefiting from the moisturizing effect of LiCl. The conductive network of MXene sheets greatly improves the ionic conductivity of the hydrogel at low temperatures, exhibiting an ionic conductivity of 1.4 S m-1 at -80 °C. Furthermore, the electronic skin assembled by the multifunctional hydrogel is efficient in monitoring human motions at -80 °C. The antifreezing and antidrying features along with favorable ionic conductivity, high tensile strength, and outstanding flexibility make the composite hydrogel promising for applications in frigid and dry regions.

A Freeze‐Resistant, Highly Stretchable and Biocompatible Organohydrogel for Non‐Delayed Wearable Sensing at Ultralow‐Temperatures

AbstractWearable electronics based on conductive hydrogels (CHs) easily suffer from prolonged response times, reduced wearing comfort, shortened service lives, and impaired signal accuracy in cold environments, because conventional CHs tend to freeze at subzero temperatures and lose their flexibility, adhesion, transparency, and conductivity, which will limit their applications in extreme environments. Inspired by the way psychrotolerant creatures and superabsorbent materials interfere with the hydrogen bonding networks of water, a freeze‐resistant conductive organohydrogel (COH) is facilely fabricated. The synergy effect between charged polar terminal groups and a binary solvent system of water–ethylene glycol weakens the hydrogen bonding between water molecules and endows the COH with remarkable freezing tolerance (−78 °C). Additionally, the obtained COH is ultra‐stretchable (≈6185%), tough (9.2 MJ m−3), highly transparent (≈99%), self‐adhesive (10.2–27.8 kPa), and biocompatible. This versatile COH is assembled into a strain sensor and a well‐designed bracelet electrocardiogram sensor. Benefiting from the exceptional low‐temperature tolerance of the prepared COH, these devices exhibit fast response with delay‐free signals even at −40 °C. Overall, this work proposes a strategy to develop multifunctional COHs for supporting human health in cold environments.

Two-dimensional assembly of gold nanoparticles grafted with charged-end-group polymers

HypothesisIntroducing charged terminal groups to polymers that graft nanoparticles enable Coulombic control over their assembly by tuning the pH and salinity of their aqueous suspensions. ExperimentsGold nanoparticles (AuNPs) are grafted with poly (ethylene glycol) (PEG) terminated with ▪ (charge-neutral), ▪ (negatively charged) or ▪ groups (positively charged), and characterized with dynamic light scattering, ζ-potential, and thermal gravimetric analysis. Liquid surface X-ray reflectivity (XR) and grazing incidence small-angle X-ray scattering (GISAXS) are used to determine the density profile and in-plane structure of the AuNPs assembly at the aqueous surface. FindingsAssembly of PEG-AuNPs at the liquid/vapor interface is tunable by adjusting pH or salinity for COOH but less for ▪ terminals. The distinct assembly behaviors are attributed to the overall charge of PEG-AuNPs as well as PEG conformation. COOH-PEG corona is more compact than those of the other terminal groups, leading to a crystalline structure with a smaller superlattice. The net charge per particle depends not only on the PEG terminal groups but also on the cation sequestration of PEG and the intrinsic negative charge of the AuNP surface. [1] The closeness to overall charge neutrality, and hydrogen bonding in play, brought by ▪-PEG, drive ▪-PEG-AuNPs to assembly and crystallinity without additives to the suspensions.

Single-Molecule Charge Transport through Positively Charged Electrostatic Anchors.

The charge transport in single-molecule junctions depends critically on the chemical identity of the anchor groups that are used to connect the molecular wires to the electrodes. In this research, we report a new anchoring strategy, called the electrostatic anchor, formed through the efficient Coulombic interaction between the gold electrodes and the positively charged pyridinium terminal groups. Our results show that these pyridinium groups serve as efficient electrostatic anchors forming robust gold-molecule-gold junctions. We have also observed binary switching in dicationic viologen molecular junctions, demonstrating an electron injection-induced redox switching in single-molecule junctions. We attribute the difference in low- and high-conductance states to a dicationic ground state and a radical cationic metastable state, respectively. Overall, this anchoring strategy and redox-switching mechanism could constitute the basis for a new class of redox-activated single-molecule switches.

The Role of Electrostatics in the Mechanism of Cardiac Thin Filament Based Sensitizers.

Heart muscle contraction is regulated by calcium binding to cardiac troponin C. This induces troponin I (cTnI) switch region binding to the regulatory domain of troponin C (cNTnC), pulling the cTnI inhibitory region off actin and triggering muscle contraction. Small molecules targeting this cNTnC-cTnI interface have potential in the treatment of heart disease. Most of these have an aromatic core which binds to the hydrophobic core of cNTnC, and a polar and often charged 'tail'. The calmodulin antagonist W7 is unique in that it acts as calcium desensitizer. W7 binds to the interface of cNTnC and cTnI switch region and weakens cTnI binding, possibly by electrostatic repulsion between the positively charged terminal amino group of W7 and the positively charged RRVR144-147 region of cTnI. To evaluate the role of electrostatics, we synthesized A7, where the amino group of W7 was replaced with a carboxyl group. We determined the high-resolution solution NMR structure of A7 bound to a cNTnC-cTnI chimera. The structure shows that A7 does not change the overall conformation of the cNTnC-cTnI interface, and the naphthalene ring of A7 sits in the same hydrophobic pocket as that of W7, but the charged tail takes a different route to the surface of the complex, especially with respect to the position of the switch region of cTnI. We measured the affinities of A7 for cNTnC and the cNTnC-cTnI complex and that of the cTnI switch peptide for the cNTnC-A7 complex. We also compared the binding of W7 and A7 for two cNTnC-cTnI chimeras, differing in the presence or absence of the RRVR region of cTnI. A7 decreased the binding affinity of cTnI to cNTnC substantially less than W7 and bound more tightly to the more positively charged chimera. We tested the effects of W7 and A7 on the force-calcium relation of demembranated rat right ventricular trabeculae and demonstrated that A7 has a much weaker desensitization effect than W7. We also synthesized A6, which has one less methylene group on the hydrocarbon chain than A7. A6 did not affect binding of cTnI switch peptide nor change the calcium sensitivity of ventricular trabeculae. These results suggest that the negative inotropic effect of W7 may result from a combination of electrostatic repulsion and steric hindrance with cTnI.

Chemical Bath Deposition of Copper Sulfide on Functionalized SAMs: An Unusual Selectivity Mechanism.

We have investigated the chemical bath deposition (CBD) of CuS using thioacetamide on functionalized self-assembled monolayers (SAMs) using scanning electron and optical microscopies, X-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectrometry. For all SAMs studied, the amount of CuS deposited is strongly dependent on the bath pH and can be attributed to the interaction of the SAM terminal groups with the chalcogenide ions present in solution. For -CH3-terminated SAMs, there is a steady increase in the amount of CuS deposited with an increase in the bath pH because there is an increase in the concentration of chalcogenide ion. However, for -OH- and -COOH-terminated SAMs, we observe that the maximum amount of CuS is deposited at pH 10. We attribute this behavior to a competition between the repulsion of the chalcogenide ions by the negatively charged SAM terminal groups and an increase in the chalcogenide ion concentration with an increase in the bath pH. Using the interaction of the chalcogenide ions with the different SAM terminal functional groups, we demonstrate that CuS can be selectively deposited on the -CH3-terminated areas of patterned -OH/-CH3- and -COOH/-CH3-terminated SAMs.

Uniform, High-Aspect-Ratio, and Patchy 2D Platelets by Living Crystallization-Driven Self-Assembly of Crystallizable Poly(ferrocenyldimethylsilane)-Based Homopolymers with Hydrophilic Charged Termini

Two-dimensional (2D) seeded growth of poly(ferrocenyldimethylsilane) (PFS) homopolymers that possess hydrophilic charged termini in solution has been investigated using the living crystallization-driven self-assembly method. The charge-terminated homopolymers, PFSn[NMe3]I, were synthesized through a combination of living anionic polymerization and post-polymerization thiol–ene “click” chemistry. Uniform and patchy high-aspect-ratio 2D structures were obtained by seeded growth in solution. We show that the aspect ratio of the resultant 2D platelets could be controlled over a wide range (ca. 2–20) by changing either the solvent polarity of the medium in which seeded growth was conducted, the substituents on the charged terminal group, or the characteristics of the seed micelle. The counteranion associated with the charge-terminated PFS[NMe3]+ homopolymers was found to have a substantial effect on the resulting morphology and colloidal stability of the resulting 2D platelets, which may be a consequence of relatively high charge density of the terminal quaternary ammonium cation.

Structure and Dynamics of Polymeric Canopies in Nanoscale Ionic Materials: An Electrical Double Layer Perspective

Nanoscale ionic materials (NIMs) are an emerging class of materials consisting of charged nanoparticles and polymeric canopies attaching to them dynamically by electrostatic interactions. Using molecular simulations, we examine the structure and dynamics of the polymeric canopies in model NIMs in which the canopy thickness is much smaller than the nanoparticle diameter. Without added electrolyte ions, the charged terminal groups of polymers adsorb strongly on charged walls, thereby electrostatically “grafting” polymers to the wall. These polymers are highly stretched. They rarely desorb from the wall, but maintain modest in-plane mobility. When electrolyte ion pairs are introduced, the counterions adsorb on the wall, causing some electrostatically “grafted” polymers to desorb. The desorbed polymers, however, are less than the adsorbed counter-ions, which leads to an overscreening of wall charges. The desorbed polymers’ charged terminal groups do not distribute uniformly across the canopy but are depleted in some regions; they adopt conformation similar to those in bulk and exchange with the “grafted” polymers rapidly, hence dilating the canopy and accelerating its dynamics. We understand these results by taking the canopy as an electrical double layer, and highlight the importance of the interplay of electrostatic and entropic effects in determining its structure and dynamics.

Long-range interfacial electron transfer and electrocatalysis of molecular scale Prussian Blue nanoparticles linked to Au(111)-electrode surfaces by different chemical contacting groups

We have explored interfacial electrochemical electron transfer (ET) and electrocatalysis of 5–6 nm Prussian Blue nanoparticles (PBNPs) immobilized on Au(111)-electrode surfaces via molecular wiring with variable-length, and differently functionalized thiol-based self-assembled molecular monolayers (SAMs). The SAMs contain positively (−NH3 +) or negatively charged (–COO–) terminal group, as well an electrostatically neutral hydrophobic terminal group (–CH3). The surface microscopic structures of the immobilized PBNPs were characterized by high-resolution atomic force microscopy (AFM) directly in aqueous electrolyte solution under the same conditions as for electrochemical measurements. The PBNPs displayed fast and reversible interfacial ET on all the surfaces, notably in multi-ET steps as reflected in narrow voltammetric peaks. The ET kinetics can be controlled by adjusting the length of the SAM forming linker molecules. The interfacial ET rate constants were found to depend exponentially on the ET distance for distances longer than a few methylene groups in the chain, with decay factors (β) of 0.9, 1.1, and 1.3 per CH2, for SAMs terminated by −NH3 +,–COO–, and–CH3, respectively. This feature suggests, first that the interfacial ET processes follow a tunneling mechanism, resembling that of metalloproteins in a similar assembly. Secondly, the electronic contact of the SAM terminal groups that anchor non-covalently the PBNP are crucial as reported for other types of molecular junctions. Highly efficient PBNP electrocatalysis of H2O2 reduction was also observed for the three linker groups, and the electrocatalytic mechanisms analyzed.

Reparametrization of Protein Force Field Nonbonded Interactions Guided by Osmotic Coefficient Measurements from Molecular Dynamics Simulations.

There is a small, but growing, body of literature describing the use of osmotic coefficient measurements to validate and reparametrize simulation force fields. Here we have investigated the ability of five very commonly used force field and water model combinations to reproduce the osmotic coefficients of seven neutral amino acids and five small molecules. The force fields tested include AMBER ff99SB-ILDN, CHARMM36, GROMOS54a7, and OPLS-AA, with the first of these tested in conjunction with the TIP3P and TIP4P-Ew water models. In general, for both the amino acids and the small molecules, the tested force fields produce computed osmotic coefficients that are lower than experiment; this is indicative of excessively favorable solute-solute interactions. The sole exception to this general trend is provided by GROMOS54a7 when applied to amino acids: in this case, the computed osmotic coefficients are consistently too high. Importantly, we show that all of the force fields tested can be made to accurately reproduce the experimental osmotic coefficients of the amino acids when minor modifications-some previously reported by others and some that are new to this study-are made to the van der Waals interactions of the charged terminal groups. Special care is required, however, when simulating Proline with a number of the force fields, and a hydroxyl-group specific modification is required in order to correct Serine and Threonine when simulated with AMBER ff99SB-ILDN. Interestingly, an alternative parametrization of the van der Waals interactions in the latter force field, proposed by the Nerenberg and Head-Gordon groups, is shown to immediately produce osmotic coefficients that are in excellent agreement with experiment. Overall, this study reinforces the idea that osmotic coefficient measurements can be used to identify general shortcomings in commonly used force fields' descriptions of solute-solute interactions and further demonstrates that modifications to van der Waals parameters provide a simple route to optimizing agreement with experiment.

Chip-scale alignment of long DNA nanofibers on a patterned self-assembled monolayer.

Controlled alignment of long DNA nanofibers is challenging. This communication reports a method to align human genomic DNA with nearly unlimited length using lithographically produced micro-patterns of self-assembled monolayers (SAMs) with positively charged terminal groups. The micro-patterns act as local DNA reservoirs to supply DNAs for nanofiber formation, and can also stretch and align DNA nanofibers to form an ordered array by controlling the dewetting profile. By reducing the size and inter-patch distance of a micro-patch, a nearly uniform array of long DNA nanofibers can be patterned over a large area. A controlled motion of a DNA containing droplet allows for free patterning of DNA nanofibers and production of complex structures without a transfer process. Bending of DNA nanofibers due to local distortion of the contact line bridges more adjacent micro-patches and increases the chance of producing continuous nanofibers. The interplay between surface tension and electrostatic attraction of positively charged micro-patterns allows the production of long DNA nanofibers in a simple yet powerful way.

Which Molecular Features Affect the Intrinsic Hepatic Clearance Rate of Ionizable Organic Chemicals in Fish?

Greater knowledge of biotransformation rates for ionizable organic compounds (IOCs) in fish is required to properly assess the bioaccumulation potential of many environmentally relevant contaminants. In this study, we measured in vitro hepatic clearance rates for 50 IOCs using a pooled batch of liver S9 fractions isolated from rainbow trout (Oncorhynchus mykiss). The IOCs included four types of strongly ionized acids (carboxylates, phenolates, sulfonates, and sulfates), three types of strongly ionized bases (primary, secondary, tertiary amines), and a pair of quaternary ammonium compounds (QACs). Included in this test set were several surfactants and a series of beta-blockers. For linear alkyl chain IOC analogues, biotransformation enzymes appeared to act directly on the charged terminal group, with the highest clearance rates for tertiary amines and sulfates and no clearance of QACs. Clearance rates for C12-IOCs were higher than those for C8-IOC analogues. Several analogue series with multiple alkyl chains, branched alkyl chains, aromatic rings, and nonaromatic rings were evaluated. The likelihood of multiple reaction pathways made it difficult to relate all differences in clearance to specific molecular features the tested IOCs. Future analysis of primary metabolites in the S9 assay is recommended to further elucidate biotransformation pathways for IOCs in fish.

Characterization of post-translationally modified peptides by hydrophilic interaction and reverse phase liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry

This work explores the use of both hydrophilic interaction liquid chromatography (HILIC) and reverse phase liquid chromatography (RPLC) for the separation and subsequent characterization of bovine caseinomacropeptide (CMP) phosphopeptides and O-glycopeptides using a quadrupole-time-of-flight (QTOF) mass spectrometer with electrospray ionization. Two neutral, ethylene bridged hybrid (BEH) amide and polyhydroxyethyl aspartamide (PHEA), and a zwitterionic, sulfobetaine (ZIC), stationary phases were used for the HILIC mode, whilst an octadecylsilane (C18) stationary phase was employed for the RPLC separation. Overall, developed HILIC-QTOF method using the ZIC or BEH amide stationary phases resulted to be the most efficient methods to separate and characterize post-translationally modified (PTM) peptides without the need of any previous fractionation or derivatization step. The separation of phosphopeptides and differently sialylated O-glycopeptides in the ZIC stationary phase was dominated by an electrostatic repulsion interaction mechanism between the negatively charged phosphate groups or sialic acid moieties and the negatively charged terminal sulfonate group of the stationary phase, whereas the separation of either non-modified peptides or neutral O-glycopeptides both free of basic amino acids was based on a partitioning mechanism. In neutral amide columns, the separation was mainly dominated by hydrophilic partitioning, leading to a higher retention of the post-translationally modified peptides than the unmodified counterparts due to the hydrophilicity provided by the phosphate groups and/or O-glycans. As a consequence, HILIC-ESI-QTOF MS operating in the positive ion mode is a powerful tool for the characterization of underivatized O-glycopeptides and phosphopeptides.

Molecular Dynamics Simulations of Hydrogen Bond Dynamics and Far-Infrared Spectra of Hydration Water Molecules around the Mixed Monolayer-Protected Au Nanoparticle

Molecular dynamics simulations have been performed to systematically investigate the structure and dynamics properties, hydrogen bond (HB) dynamics, and far-infrared (far-IR) spectra of hydration water molecules around the mixed monolayer-protected Au nanoparticles (MPANs) with different ligand compositions and length. Our simulation results demonstrate that the translational and rotational motions of hydration water molecules in the proximity of charged terminal NH3+ and COO– groups are suppressed significantly with respect to the bulk water. Compared to the bulk water, meanwhile, longer structural relaxation times of hydration H2O–H2O HBs indicate enhanced strength of H2O–H2O HBs at the interface of mixed MPANs. Accordingly, these hydration water molecules around the charged terminal groups can exhibit a considerable blue-shift in far-IR spectra for all ligand compositions and length studied here. A series of detailed HB analyses manifest that above restricted behavior of hydration water molecules can b...

Does symmetry of branching affect the properties of dendrimers?

Statistical properties of second- to sixth- generation dendrimers with symmetric and asymmetric branching were investigated via Langevin dynamics in dilute solutions with the use of a coarse-grained model. The cases of charged and neutral terminal groups are discussed. Steric interactions were controlled by repulsive forces, a circumstance that corresponded to an athermal solvent. Electrostatic interactions were taken into account via the Ewald method. The size and shape of macromolecules; the density profiles for monomer units and, separately, for terminal groups; and the effective charge of a dendrimer as a function of the generation number were determined. It is shown that the equilibrium characteristics of dendrimers with symmetric and asymmetric branching are similar if the average lengths of their spacers coincide. Branching asymmetry appeared itself only in increased “turning back” of short spacers relative to their longer neighbors’ arising from the same branching point.

Interaction of bolaform surfactants with p-sulfonatocalix[4]arene: the role of two positive charges in the binding.

The inclusion binding manners of bolaform surfactants of type C(n)R6(2+) 2Br(-) with different spacer lengths (n = 6, 12) and terminal headgroup volumes (R = methyl, ethyl) by p-sulfonatocalix[4]arene were studied. The combination of ITC parameters (binding constants and complexation enthalpy and entropy) and NMR chemical shifts and NOE cross-peaks obtained upon complexation allows us to propose different binding modes. The results point out that the spacer length has an influence on the binding stoichiometry. The bolaforms with larger spacer lengths between polar head groups enable the formation of 2:1 complexes in addition to 1:1, while with the shorter spacer they form only 1:1 complexes. On the other hand, the formation of 1:1 complexes is not affected by the headgroup volume or the spacer length of the bolaform. Unexpectedly, a complex binding mode was observed where both positive charged terminal groups of the bolaform are accommodated in the cavity of the calixarene. The inclusion of both terminal groups of the guests can be related to its own structure but also evidence the high flexibility of the calixarene.

Disorder and order in unfolded and disordered peptides and proteins: A view derived from tripeptide conformational analysis. II. Tripeptides with short side chains populating asx and β‐type like turn conformations

In the preceding paper, we found that ensembles of tripeptides with long or bulky chains can include up to 20% of various turns. Here, we determine the structural and thermodynamic characteristics of GxG peptides with short polar and/or ionizable central residues (D, N, C), whose conformational distributions exhibit higher than average percentage (>20%) of turn conformations. To probe the side-chain conformations of these peptides, we determined the (3)J(H(α),H(β)) coupling constants and derived the population of three rotamers with χ1 -angles of -60°, 180° and 60°, which were correlated with residue propensities by DFT-calculations. For protonated GDG, the rotamer distribution provides additional evidence for asx-turns. A comparison of vibrational spectra and NMR coupling constants of protonated GDG, ionized GDG, and the protonated aspartic acid dipeptide revealed that side chain protonation increases the pPII content at the expense of turn populations. The charged terminal groups, however, have negligible influence on the conformational properties of the central residue. Like protonated GDG, cationic GCG samples asx-turns to a significant extent. The temperature dependence of the UVCD spectra and (3)J(H(N)H(α)) constants suggest that the turn populations of GDG and GNG are practically temperature-independent, indicating enthalpic and entropic stabilization. The temperature-independent J-coupling and UVCD spectra of GNG require a three-state model. Our results indicate that short side chains with hydrogen bonding capability in GxG segments of proteins may serve as hinge regions for establishing compact structures of unfolded proteins and peptides.

Biological properties of water-soluble phosphorhydrazone dendrimers

Dendrimers are hyperbranched and perfectly defined macromolecules, constituted of branches emanating from a central core in an iterative fashion. Phosphorhydrazone dendrimers constitute a special family of dendrimers, possessing one phosphorus atom at each branching point. The internal structure of these dendrimers is hydrophobic, but hydrophilic terminal groups can induce the solubility of the whole structure in water. Indeed, the properties of these compounds are mainly driven by the type of terminal groups their bear; this is especially true for the biological properties. For instance, positively charged terminal groups are efficient for transfection experiments, as drug carriers, as anti-prion agents, and as inhibitor of the aggregation of Alzheimer's peptides, whereas negatively charged dendrimers have anti-HIV properties and can influence the human immune system, leading to anti-inflammatory properties usable against rheumatoid arthritis. This review will give the most representative examples of the biological properties of water-soluble phosphorhydrazone dendrimers, organized depending on the type of terminal groups they bear.

Positively Charged Dendron Micelles Display Negligible Cellular Interactions

PEGylated dendron-based copolymers (PDC) with different end-group functionalities (-NH(2), -COOH, and -Ac) were synthesized and self-assembled into dendron micelles to investigate the effect of terminal surface charges on size, morphology, and cellular interactions of the micelles. All of the dendron micelles exhibited similar sizes (20-60 nm) and spherical morphologies, as measured using dynamic light scattering and transmission electron microscopy, respectively. The cellular interactions of dendron micelles were evaluated using confocal microscopy and flow cytometry. Surprisingly, although amine-terminated dendrimers are known to strongly interact with cells non-specifically, all of the surface-modified dendron micelles exhibited charge-independent low-levels of cellular interaction. The unexpected results, particularly from the amine-terminated dendron micelles, could be attributed to: i) minimal end-group effects, as each PDC has an approximately 10-fold lower charge-number-to-molecular-weight ratio compared to the dendrimer; and ii) intra- and intermolecular hydrogen bonding between positively charged terminal groups with poly(ethylene glycol) (PEG) backbones, which leads to the sequestration of the charges, as demonstrated by atomistic molecular dynamics simulations. With the narrow size distribution, uniform morphologies, and low levels of non-specific cellular interactions, the dendron micelles offer a promising drug delivery platform.

Monte Carlo simulations of charged dendrimer-linear polyelectrolyte complexes and explicit counterions

We study complexes composed of one dendrimer of generation G = 4 (G4 dendrimer) with N(t) = 32 charged terminal groups and an oppositely charged linear polyelectrolyte accompanied by neutralizing counterions in an athermal solvent using Monte Carlo simulations based on the bond fluctuation model. In our study both the full Coulomb potential and the excluded volume interactions are taken into account explicitly with the reduced temperature τ and the chain length N(ch) as the main simulation parameters. Our calculations indicate that there exist three temperature ranges that determine the behavior of such complexes. At τ(complex) stable charged dendrimer-linear polyelectrolyte complexes are formed first, which are subsequently accompanied by selective counterion localization within the complex interior at τ(loc) ≤ τ(complex), and counterion condensation as temperature is further decreased below τ(cond) < τ(loc). In particular, we observe that condensation takes place exclusively on the excess charges in the complex and thus no condensation is observed at the compensation point (N(ch) = N(t)), irrespective of τ. For N(ch) ≠ N(t) the complex is overally charged. Furthermore, we discuss the size and structure of the dendrimer and the linear polyelectrolyte within the complex, as well as spatial distributions of monomers and counterions. Conformations of the chain in the bound state are analysed in terms of loops, trains, and tails.