Cs Complex Research Articles

Picoplatin (II)-loaded chitosan nanocomposites as effective drug delivery systems: Preparation, mechanistic investigation of BSA/5-GMP/GSH binding and biological evaluations

The goal of the current study is to improve the characteristics and bioavailability of the drug picoplatin (PPt) by encapsulating it in chitosan nanoparticles (CS NPs) which allows for the targeted delivery of cytotoxic cargo to cancerous tissue, reducing toxic side effects and raising the therapeutic index. When picoplatin was delivered into the CS, it was able to produce a complex with CS (PPt@CS NPs) that had an appropriate particle size of 275 ± 10 nm, a reasonably low PDI of 0.15 ± 0.05, and high stability (ζ = −22.1 ± 0.3 mV). Since almost all pharmaceuticals work by binding to specific proteins or DNA, the in vitro binding mechanism and affinity of bovine serum albumin (BSA), low molecular building units of nucleic acids (5−GMP), and Glutathione (GSH) (considering that cisplatin resistance could be due to a reaction between cisplatin and GSH) to PPt and PPt@CS NPs were examined using stopped-flow and other spectroscopic approaches. Through two reversible processes, a rapid second-order binding followed by a slower first-order isomerization reaction, and a static quenching mechanism, PPt and PPt@CS NPs bind to BSA with relative reactivity of around (PPt)/(PPt@CS NPs) = 1/2.5. The 5−GMP interaction studies demonstrated that, in addition to changing the binding mechanism, PPt's encapsulation in CS increases its rate of reaction through coordination affinity. PPt interacted with 5-GMP via two reversible processes, a rapid second-order binding to phosphate followed by a slower first−order migration to the N7 of pyrimidine moiety. PPt@CS NPs showed weaker binding to GSH compared to PPt and hence PPt@CS NPs exhibits a lower resistance factor. It was also found that the in vitro drug release of PPt@CS NPs in PBS at pH 7.4 was steady, releasing 30 % of the PPt in just 5 h. Nonetheless, 75 % of the release in a pH 5.4 solution containing 10 mM GSH—a solution that mimics the tumor microenvironment—shows that the PPt@CS NPs system is sensitive to GSH and specifically targets malignant tissue. The encapsulation of PPt in CS complex maintained its anticancer activity, as shown by an in vitro cell-survival assay on HepG2 cancer cell lines and also cleavage efficiency toward the minor groove of pBR322 DNA via the hydrolytic way. These findings collectively suggested that inclusion PPt in CS would be an effective strategy to formulate a novel picoplatin formulation intended for use as targeted anticancer treatment.

The Sensitivity of Structure to Ionic Radius and Reaction Stoichiometry: A Crystallographic Study of Metal Coordination and Hydrogen Bonding in Barbiturate Complexes of All Five Alkali Metals Li-Cs.

A systematic study has been conducted on barbiturate complexes of all five alkali metals, Li-Cs, prepared from metal carbonates or hydroxides in an aqueous solution without other potential ligands present, varying the stoichiometric ratio of metal ion to barbituric acid (BAH). Eight polymeric coordination compounds (two each for Na, K, and Rb and one each for Li and Cs) have been characterised by single-crystal X-ray diffraction. All contain some combination of barbiturate anion BA- (necessarily in a 1:1 ratio with the metal cation M+), barbituric acid, and water. All organic species and water molecules are coordinated to the metal centres via oxygen atoms as either terminal or bridging ligands. Coordination numbers range from 4 (for the Li complex) to 8 (for the Cs complex). Extensive hydrogen bonding plays a significant role in all the crystal structures, almost all of which include pairs of N-H···O hydrogen bonds linking BA- and/or BAH components into ribbons extending in one dimension. Factors influencing the structure adopted by each compound include cation size and reaction stoichiometry as well as hydrogen bonding.

Preparation of pH-stabilized microcapsules for controlled release of DEET via novel CS deposition and complex coacervation

In order to slow down the volatilization rate of N, N-Diethyl-m-toluidine (DEET) and enhance its safe application, an improved complex coacervation method was developed to encapsulated it to prepare microcapsules with the function of mosquito repellent. Tannic acid as a cross-linking agent for gelatin and Arabic gum enhanced the structural stability of the capsule through hydrogen bonding. Chitosan was selected to further deposited on the surface of G/AG MC for the improvement of pH stability and formed CS-G/AG MC. Scanning electron microscopy and optical microscope confirmed the chitosan was successful deposited on the G/AG MC, which ameliorated the agglomeration of microcapsules and promoted their monodispersity. Fourier transform infrared spectroscopy confirmed that electrostatic attraction accounted predominantly for the forces between the shell materials. The deposition of chitosan imparted controlled release to the microcapsules, resulting in a high retention efficacy of DEET in the pH range of 2–10. The CS-G/AG MC showed good storage stability and biocompatibility, and the static leakage of DEET within 40 days was negligible. The microcapsules prepared by this method showed green ecological properties, derived from the natural origin and biocompatibility of the shell material. And the tight structure of the microcapsule shell effectively barriered the volatile of DEET, while greatly extending its release time. This study can effectively protect the biological activity of core materials of microcapsules, and has long-lasting release performance, which has potential economic benefits in personal care products market directly contacted by humans.

Electrophoretic Deposition and Characterization of Functional Coatings Based on an Antibacterial Gallium (III)-Chitosan Complex

Despite their broad biomedical applications in orthopedics and dentistry, metallic implants are still associated with failures due to their lack of surface biofunctionality, leading to prosthesis-related microbial infections. In order to address this issue, the current study focuses on the fabrication and characterization of a novel type of antibacterial coating based on gallium (III)-chitosan (Ga (III)-CS) complex layers deposited on metallic substrates via electrophoretic deposition (EPD). Aiming for the production of homogeneous and monophasic coatings, a two step-procedure was applied: the first step involved the synthesis of the Ga (III)-CS complex, followed by EPD from suitable solutions in an acetic acid–aqueous solvent. The influence of Ga (III) concentration on the stability of the suspensions was evaluated in terms of zeta potential. Fourier transform infrared (FTIR) and energy dispersive X-ray (EDX) spectroscopic analyses indicated the chelation of CS with Ga (III) within the coatings, while scanning electron microscopy (SEM) confirmed that no additional metallic gallium deposited during EPD. Furthermore, the results demonstrated that the wettability, mechanical properties, swelling ability, and enzymatic degradation of the coatings were affected by the quantity of Ga (III) ions. Colony forming unit (CFU) tests showed a strong synergistic effect between CS and Ga (III) in inhibiting Escherichia coli strain growth compared to control CS samples. An in vitro study with MG-63 cells showed that Ga (III)-containing coatings were not toxic after 24 h of incubation.

Unique Complexation Behavior of Alkali Metal Ions and 2-Pyrone-4,6-Dicarboxylic Acid (PDC) Obtained from a Metabolic Intermediate of Lignin

The complexation behavior between 2-pyrone-4,6-dicarboxylic acid (PDC) and alkali metal ions was systematically estimated. The PDC complexes of alkali metal ions exhibit unique crystal structures due to the diverse coordination numbers of the metal ion. The crystal structure of the complex between PDC and cesium (Cs) ion suggests that the metal ion binary crosslinking and much coordination numbers of the Cs induce the preferential complex formation via sedimentation of the PDC–Cs complex. The minor electronegativity difference between the Cs and other alkali metals might be the determining factor in the structure of the complex the ion forms with PDC.

Biochemical and Spectroscopic Characterization of Highly Stable Photosystem II Supercomplexes from Arabidopsis

Photosystem II (PSII) is a large membrane supercomplex involved in the first step of oxygenic photosynthesis. It is organized as a dimer, with each monomer consisting of more than 20 subunits as well as several cofactors, including chlorophyll and carotenoid pigments, lipids, and ions. The isolation of stable and homogeneous PSII supercomplexes from plants has been a hindrance for their deep structural and functional characterization. In recent years, purification of complexes with different antenna sizes was achieved with mild detergent solubilization of photosynthetic membranes and fractionation on a sucrose gradient, but these preparations were only stable in the cold for a few hours. In this work, we present an improved protocol to obtain plant PSII supercomplexes that are stable for several hours/days at a wide range of temperatures and can be concentrated without degradation. Biochemical and spectroscopic properties of the purified PSII are presented, as well as a study of the complex solubility in the presence of salts. We also tested the impact of a large panel of detergents on PSII stability and found that very few are able to maintain the integrity of PSII. Such new PSII preparation opens the possibility of performing experiments that require room temperature conditions and/or high protein concentrations, and thus it will allow more detailed investigations into the structure and molecular mechanisms that underlie plant PSII function.

Molecular CsF5 and CsF2+.

D5h star-like CsF5 , formally isoelectronic with known XeF5 (-) ion, is computed to be a local minimum on the potential energy surface of CsF5 , surrounded by reasonably large activation energies for its exothermic decomposition to CsF+2 F2 , or to CsF3 (three isomeric forms)+F2 , or for rearrangement to a significantly more stable isomer, a classical Cs(+) complex of F5 (-) . Similarly the CsF2 (+) ion is computed to be metastable in two isomeric forms. In the more symmetrical structures of these molecules there is definite involvement in bonding of the formally core 5p levels of Cs.

Improvement of electron injection of organic light-emitting devices by inserting a thin aluminum layer into cesium carbonate injection layer**Project supported by the National Natural Science Foundation of China (Grant No. 60906022), the Natural Science Foundation of Tianjin, China (Grant No. 10JCYBJC01100), the Scientific Developing Foundation of Tianjin Education Commission, China (Grant No. 2011ZD02), the Key Science and Technology Support Program

We investigate the electron injection effect of inserting a thin aluminum (Al) layer into cesium carbonate (Cs2CO3) injection layer. Two groups of organic light-emitting devices (OLEDs) are fabricated. For the first group of devices based on Alq3, we insert a thin Al layer of different thickness into Cs2CO3 injection layer, and the device's maximum current efficiency of 6.5 cd/A is obtained when the thickness of the thin Al layer is 0.4 nm. However, when the thickness of Al layer is 0.8 nm, the capacity of electron injection is the strongest. To validate the universality of this approach, then we fabricate another group of devices based on another blue emitting material. The maximum current efficiency of the device without and with a thin Al layer is 4.51 cd/A and 4.84 cd/A, respectively. Inserting a thin Al layer of an appropriate thickness into Cs2CO3 layer can result in the reduction of electron injection barrier, enhancement of the electron injection, and improvement of the performance of OLEDs. This can be attributed to the mechanism that thermally evaporated Cs2CO3 decomposes into cesium oxides, the thin Al layer reacts with cesium oxides to form Al–O–Cs complex, and the amount of the Al–O–Cs complex can be controlled by adjusting the thickness of the thin Al layer.

Multi-walled carbon nanotubes–chitosan with a branched structure modified with ferrocenecarboxylic acid for carcinoembryonic antigen detection

A novel electrochemical immunosensor for the detection of CEA was proposed based on Fc-COOH connected to the branched structure of a MWCNT–CS complex modified electrode.

Inhibition of influenza virus infection with chitosan–sialyloligosaccharides ionic complex

With the recent emergence of drug-resistant influenza viruses, effective means of preventing and treating these contagious pathogens have become imperative. The binding receptors of influenza virus are sialyloligosaccharides (SOS), which are present on the surfaces of host cells, and are therefore attractive targets for antiviral development. We report the preparation and identification of a novel influenza virus entry inhibitor, designated chitosan–SOS complex (CS complex). The CS complex was formed through noncovalent adsorption between cationic chitosan and anionic SOS, the latter derived from bovine colostrum. The preparation was accomplished in gram quantities from chitosan and bovine colostrum oligosaccharides by a one-step dialysis process. The inhibitory activity of the complex against influenza virus infection was determined by cytotoxicity inhibition assay (IC50=42μM). This simple preparation, combined with efficient anti-infective activity and the rich natural availability of chitosan and SOS, highlights the potential of the CS complex as a safe, practical agent for influenza prevention and control.

2P085 CS複合体形成をモデルとした高感度ペプチド-タンパク質間相互作用検出系のデザイン(01F. 蛋白質:蛋白質工学/進化工学,ポスター,第52回日本生物物理学会年会(2014年度))

2P085 CS複合体形成をモデルとした高感度ペプチド-タンパク質間相互作用検出系のデザイン(01F. 蛋白質:蛋白質工学/進化工学,ポスター,第52回日本生物物理学会年会(2014年度))

Two Weeks of Metformin Treatment Enhances Mitochondrial Respiration in Skeletal Muscle of AMPK Kinase Dead but Not Wild Type Mice

Metformin is used as an anti-diabetic drug. Metformin ameliorates insulin resistance by improving insulin sensitivity in liver and skeletal muscle. Reduced mitochondrial content has been reported in type 2 diabetic muscles and it may contribute to decreased insulin sensitivity characteristic for diabetic muscles. The molecular mechanism behind the effect of metformin is not fully clarified but inhibition of complex I in the mitochondria and also activation of the 5′AMP activated protein kinase (AMPK) has been reported in muscle. Furthermore, both AMPK activation and metformin treatment have been associated with stimulation of mitochondrial function and biogenesis. However, a causal relationship in skeletal muscle has not been investigated. We hypothesized that potential effects of in vivo metformin treatment on mitochondrial function and protein expressions in skeletal muscle are dependent upon AMPK signaling. We investigated this by two weeks of oral metformin treatment of muscle specific kinase dead α2 (KD) AMPK mice and wild type (WT) littermates. We measured mitochondrial respiration and protein activity and expressions of key enzymes involved in mitochondrial carbohydrate and fat metabolism and oxidative phosphorylation. Mitochondrial respiration, HAD and CS activity, PDH and complex I-V and cytochrome c protein expression were all reduced in AMPK KD compared to WT tibialis anterior muscles. Surprisingly, metformin treatment only enhanced respiration in AMPK KD mice and thereby rescued the respiration defect compared to the WT mice. Metformin did not influence protein activities or expressions in either WT or AMPK KD mice.We conclude that two weeks of in vivo metformin treatment enhances mitochondrial respiration in the mitochondrial deficient AMPK KD but not WT mice. The improvement seems to be unrelated to AMPK, and does not involve changes in key mitochondrial proteins.

Complexation of the cesium cation with 1,3-alternate-25,27-bis(1-octyloxy)calix[4]arene-crown-6

From extraction experiments and c-activity measurements, the extraction constant corresponding to the equilibrium Cs(aq) ? I(aq) ? 1(nb) , 1 Cs(nb) ? I(nb) taking place in the two–phase water–nitrobenzene system (1 = 1,3-alternate-25,27-bis(1-octyloxy)calix[4]arene-crown6; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log Kex (1 Cs, I) = 2.9 ± 0.1. Further, the stability constant of the 1 Cs complex in nitrobenzene saturated with water was calculated for a temperature of 25 C: log bnb (1 Cs) = 8.8 ± 0.1. Finally, by using quantum–mechanical DFT calculations, the most probable structure of the resulting cationic complex species 1 Cs was derived.

Aromaticity of heptafulvene charge transfer complexes with lithium and caesium atoms: A computational approach

Geometry optimization of heptafulvene complexes with Li and Cs atoms at B3LYP/6-311++G(d,p) level of theory using Gaussian 03 software allowed us to estimate the magnitude of charge transfer from metal atoms to the heptafulvene moiety (charges equal to +0.938 and +0.994 for Li and Cs, respectively) and energies of dissociation of the complex (−36.65 and −20.44kcal/mol, respectively). A substantial increase of aromatic character of the ring results from the charge transfer leading to aromaticity index HOMA equal 0.439 and 0.515, for Li and Cs complex respectively, comparing to HOMA=0.165 for isolated heptafulvene.

Immobilized Boron-Centered Heteroscorpionates: Heterocycle Metathesis and Coordination Chemistry

The preparation of a resin-supported boron-scorpionate ligand and its nickel(II) coordination complexes are reported. The supported ligand is prepared as its potassium salt, making it a general reagent suitable for chelation of any transition metal ion. Resin-immobilized benzotriazole (Bead-btz) reacted cleanly with KTp* (Tp* = hydrotris(3,5-dimethylpyrazolyl)borate) by heterocycle metathesis in warm dimethylformamide (DMF) to yield bead-Tp'K, {resin-btz(H)B(pz*)(2)}K. Significantly, bead-Tp'K readily bound nickel(II) from simple salts with minimal leaching of the nickel ion. Bead-Tp'NiNO(3) reacts further with cysteine thiolate (ethyl ester), imparting the deep green color to the beads characteristic of a Tp(R)NiCysEt coordination sphere. Bead-Tp'NiCysEt exhibited an oxygen sensitivity similar to Tp*NiCysEt in solution (Inorg. Chem. 1999, p 5690) and also independently verified for a selenocystamine analogue, Tp*NiSeCysAm. Addition of fresh cysteine thiolate ethyl ester to oxidized bead-Tp'NiCysEt reproduced the original green color. Heterocycle metathesis was also used to prepare KTp' as a white solid. Reaction with nickel(II) gave (Tp')(2)Ni, separable into two different isomers. The air-sensitive molybdenum(0) complex, [PPh(4)][Tp'Mo(CO)(3)], was also prepared and the C(s) complex symmetry demonstrated by infrared and (13)C NMR spectroscopies. Immobilized TpmMo(CO)(3) was prepared from the previously reported resin-supported tris(pyrazolyl)methane. In contrast to its weak coordination of nickel(II) (Inorg. Chem. 2009, p 3535), bead-Tpm proved a strong chelate toward this second row metal. The supported scorpionates described here should find use in studies of selective metal-protein binding, metalloprotein modeling, and heterogeneous catalysis, and render such scorpionate applications amenable to combinatorial methods.

Reactions of CO2 and CS2 with 1,2-Bis(di-tert-butylphosphino)ethane Complexes of Nickel(0) and Nickel(I)

Reaction of CS(2) with [(dtbpe)Ni](2)(η(2),μ-C(6)H(6)) (1; dtbpe =1,2-bis(di-tert-butylphosphino)ethane) in toluene gives the carbon disulfide complex (dtbpe)Ni(η(2)-CS(2)) (2), characterized by standard spectroscopic methods and X-ray crystallography. Reaction of CS(2) with the Ni(I) complex (dtbpe)Ni(OSO(2)CF(3)) gives the diamagnetic, trimetallic cluster [{(dtbpe)Ni(κ(1),η(2)-CS(2))}(2)(dtbpe)Ni][SO(3)CF(3)](2) (3-OTf). The solid-state structure of 3-OTf reveals that the two CS(2) ligands bind η(2) to two (dtbpe)Ni centers and κ(1) to the third, unique (dtbpe)Ni in the complex dication, and NMR spectroscopic data indicate that this structure is maintained in solution. Oxidation of 2 by ferrocenium hexafluorophosphate affords the identical trimetallic complex dication as the PF(6)(-) salt, [{(dtbpe)Ni(κ(1),η(2)-CS(2))}(2)(dtbpe)Ni][PF(6)](2) (3-PF(6)). These results are consistent with the intermediacy of a Ni(I)-CS(2) complex, [(dtbpe)Ni(CS(2))(+)], that is unstable with respect to disproportionation. Reaction of 1 with one equivalent of CO(2) provides the carbon dioxide adduct (dtbpe)Ni(η(2)-CO(2)) (4), that was also crystallographically characterized. Thermolysis of 4 in benzene solution at 80 °C results in reduction of the CO(2) ligand to CO, trapped as (dtbpe)Ni(CO)(2), and partial oxidation of a dtbpe ligand to give O═P(tert-Bu)(2)CH(2)CH(2)P(tert-Bu)(2).

Norbadione A: Kinetics and Thermodynamics of Cesium Uptake in Aqueous and Alcoholic Media

Norbadione A (NbA) is a mushroom pigment, which is assumed to be involved in (137)Cs accumulation all over Europe during the Chernobyl nuclear accident. NbA bears seven acid-base functional groups, among which are two enolic and two carboxylic acid moieties. This work deals with complex formation of Cs(+) and NbA in ethanol, ethanol/water (9:1) (M1), and water with, when required, the support of two Cs(+) ionophore probes, calix[4]arene-bis(crown-6-ether)dioxycoumarine (A1) and its tetrasuslfonated form (A2). In ethanol, two Cs(+) complexes are formed, with the affinity constants K(1EtOH) = (1.1 ± 0.25) × 10(5) and K(2EtOH) = (2.1 ± 0.4) × 10(3). In M1, a single Cs(+) complex occurs when only the enols are deprotonated, whereas a bicomplex is formed when both enols and carboxylic acids are deprotonated: K(1M1) = (1.5 ± 0.3) × 10(5) and K(2M1) = (4 ± 2) × 10(3). These data are confirmed by stopped-flow and T-jump kinetics. In ethanol, a fast Cs(+) exchange occurs between NbA and A1: direct rate constant, k(1) = (3.1 ± 0.1) × 10(7) M(-1) s(-1); reverse rate constant k(-1) = (2.8 ± 1) × 10(5) M(-1) s(-1); and Cs(+) exchange constant, K(1Exchange) = (9 ± 4) × 10(-3). In M1, the quenching of A2 fluorescence by NbA is used to determine the kinetics of complex formation with Cs(+): k(2) = (1.8 ± 0.4) × 10(9) M(-1) s(-1); k(-2) = (1.80 ± 0.15) × 10(4) s(-1); and K(1M1) = (1.5 ± 0.5) × 10(5). The affinity of NbA for Cs(+) is probably the result of the particular structure in which the two pulvinic acid arms adopt a conformation that forms two complexation sites composed of the two enolates and/or the two carboxylates. This renders the efficiency in Cs(+) uptake comparable to that of some calixarenes or crown ethers.

Conformations and vibrational spectroscopy of metal-ion/polylalanine complexes

The thermochemistry and structures of complexes of dialanine and trialanine with a series of singly and doubly charged metal ions have been examined by spectroscopic and computational approaches. Complexes with Li +, K +, Cs +, Ca 2+, Sr 2+ and Ba 2+ were formed by electrospray ionization, and studied by infrared multiple photon dissociation spectroscopy (IRMPD) in a Fourier-transform ion cyclotron resonance (FTICR) mass spectrometer using irradiation in the 1000–1900 cm −1 infrared (IR) region from the FELIX free electron laser. Spectra were correlated with computed thermochemistry and simulated IR spectra from density functional (DFT) calculations of likely candidate conformations to make conformational assignments and characterize the variation of characteristic normal mode frequencies as a function of metal-ion identity. All trialanine complexes were found to have the charge-solvated (CS) form of the ligand with all three carbonyl oxygens chelating the metal. Dialanine was more varied: the Ba complex had largely the salt-bridge (SB) form, the Sr and Ca complexes showed a mixture of CS and SB, the Cs complex was CS with (OO) chelation, and the K, Na and Li complexes were CS in an undetermined mixture of (OO) and (NOO) chelation. Binding of the metal ion to the carboxyl carbonyl and to the amide carbonyl(s) (Amide I band) gave a red shift of the C O stretches, and a blue shift to the Amide II band. The frequency shifts were greater for more strongly interacting metal ions (smaller size, larger charge), and were found to be linearly proportional to the metal–ligand binding energy.

Preparation and characterization of dicesium tetravalent plutonium hexanitrate

Abstract In experiments on U crystallization in a dissolver solution containing Cs, there is concern that Cs and Pu(IV) nitrate complex are deposited on the UNH crystal in the dissolver solution at the time of the U crystallization. The characteristics of generation of Cs and Pu(IV) nitrate complex with dissolver solution of MOX fuel were examined. This complex was obtained as a precipitate by mixing dissolver solution of MOX fuel and CsNO3 solution, and was identified as dicesium tetravalent plutonium hexanitrate, Cs2Pu(NO3)6 by concentration analysis and XRD. The precipitate has a tendency to be generated at high HNO3 concentrations. Thermal analysis shows that the precipitate is stable below 245 °C, and a weight loss of 10.29 ± 0.23% is observed between 245 and 297 °C. This result indicates the decomposition of Cs2Pu(NO3)6 to Cs2PuO2(NO3)4. With these properties, the UNH crystal should melt at the condition between 60 and 100 °C and be separable from the Cs complex by filtration. This suggests a new method of crystal purification allowing higher decontamination of UNH crystal in the U crystallization process.

Cover Picture: Low‐Work‐Function Surface Formed by Solution‐Processed and Thermally Deposited Nanoscale Layers of Cesium Carbonate (Adv. Funct. Mater. 12/2007)

AbstractThe cover shows the structure of an efficient polymer light emitting diode (PLED) and its energy diagram at the interface between aluminum (Al) and a Cs2CO3 interfacial layer. It reveals the origin of enhanced electron injection from the Al electrode due to the low work function of a thermally evaporated Cs2CO3 layer, as reported on p. 1966 by Jinsong Huang, Zhen Xu, and Yang Yang. Pictures of the white‐ and red‐emitting PLEDs are also shown.Nanostructured layers of Cs2CO3 are shown to function very effectively as cathodes in organic electronic devices because of their good electron‐injection capabilities. Here, we report a comprehensive study of the origin of the low work function of nanostructured layers of Cs2CO3 prepared by solution deposition and thermal evaporation. The nanoscale Cs2CO3 layers are probed by various characterization methods including current–voltage (I–V) measurements, photovoltaic studies, X‐ray photoelectron spectroscopy (XPS), UV photoelectron spectroscopy (UPS), and impedance spectroscopy. It is found that thermally evaporated Cs2CO3 decomposes into CsO2 and cesium suboxides. The cesium suboxides dope CsO2, yielding a heavily doped n‐type semiconductor with an intrinsically low work function. As a result, devices fabricated using thermally evaporated Cs2CO3 are relatively insensitive to the choice of the cathode metal. The reaction of thermally evaporated Cs2CO3 with Al can further reduce the work function to 2.1 eV by forming an Al–O–Cs complex. Solution‐processed Cs2CO3 also reduces the work function of Au substrates from 5.1 to 3.5 eV. However, devices prepared using solution‐processed Cs2CO3 exhibit high efficiency only if a reactive metal such as Al or Ca is used as the cathode metal. A strong chemical reaction occurs between spin‐coated Cs2CO3 and thermally evaporated Al. An Al–O—Cs complex is formed as a result of this chemical reaction at the interface, and this layer significantly reduces the work function of the cathode. Finally, impedance spectroscopy results prove that this layer is highly conductive.