Phenoxide Groups Research Articles

Electronic and steric effects of substituents in series of Zn2+ asymmetrical bis-Schiff-base ligands complexes on catalytic ring-opening copolymerization of CHO and MA

Based on the half-unit Schiff-base ligand HL and series of asymmetrical bis-Schiff-base ligand H2Ln (n = 1–6) in situ synthesized from the reaction of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP), o-phenylenediamine, and/or different salicylaldehyde derivatives, complexes [Zn(L)2] (1) and series of [Zn(Ln)] (n = 1–6, 2–7) are obtained, respectively. Complex 1 proves to be inactive, resulting from its saturated octahedral coordination environment around the central Zn2+ ion, while in complexes 2–7, the unsaturated coordination environment for the catalytic active centers (Zn2+ ions) permits the monomer insertion for the effective bulk or solution copolymerization of CHO (cyclohexene oxide) and MA (maleic anhydride). As to the electron and steric effect in complexes 2–7 on the catalytic behaviors, the copolymerization results show that the introduction of withdrawing –Br substituent para to the phenoxide group endows higher reactive activity, while the bulkiness effect of the encumbering substituent (–Br, –OMe or tert-butyl) ortho to the phenoxide groups is in favor of the chain growth of the copolymers. Moreover, all the bulk copolymerizations in 2-7/DMAP (4-(dimethylamino)pyridine) systems afford poly(ester-co-ether)s, while lower catalyst and co-catalyst concentration for 3/DMAP system is helpful for the formation of perfectly alternating polyester in solution. Of the three co-catalysts, DMAP is found to be the most efficient, while an excess thereof is detrimental for the chain growth of the copolymers.

Group iv complexes containing the benzotriazole phenoxide ligand as catalysts for the ring-opening polymerization of lactides, epoxides and as precatalysts for the polymerization of ethylene

A series of Ti(IV), Zr(IV) and Hf(IV) benzotriazole phenoxide (BTP) complexes were synthesized and characterized by various spectroscopic techniques, elemental analysis and X-ray crystallography. The monosubstituted Zr(IV) BTP complexes [(μ-L)Zr(O(i)Pr)3]2 1-3 [L = (C1)BTP-H (1), (TCl)BTP-H (2), (pent)BTP-H (3)] and tetrasubstituted Zr(IV), Hf(IV) complexes ZrL4 4-6 [L = (C1)BTP-H (4), (TCl)BTP-H (5), (pent)BTP-H (6)] and HfL4 7-9 [L = (C1)BTP-H (7), (TCl)BTP-H (8), (pent)BTP-H (9)] were prepared by the reaction of Zr(O(i)Pr)4·((i)PrOH) and Hf(O(t)Bu)4 in toluene with the respective ligands in different stoichiometric proportions. The reaction between BTP and TiCl4 and ZrCl4 and HfCl4 in a 2 : 1 stoichiometric reaction resulted in the formation of disubstituted group IV chloride complexes L2MCl2 10-12 [L = (C1)BTP-H, M = Ti, Zr and Hf]. The molecular structures of complexes 1, 4, 7, 10, 11, and 12 were determined by single-crystal X-ray studies. The X-ray structure of 1 reveals a dimeric Zr(IV) complex containing a Zr2O2 core bridged through the oxygen atoms of the phenoxide groups. Each Zr atom is distorted from an octahedral symmetry. These complexes were found to be active towards the ring-opening polymerization (ROP) of L-lactide (L-LA) and rac-lactide (rac-LA). Complex 1 produced highly heterotactic poly(lactic acid) (PLA) from rac-LA under melt conditions with narrow molecular weight distributions (MWDs) and well controlled number average molecular weights (M(n)). Additionally, epoxide polymerizations using rac-cyclohexene oxide (CHO), rac-propylene oxide (PO), and rac-styrene oxide (SO) were also carried out with these complexes. The yield and molecular weight of the polymer was found to increase with the extension of reaction time. Compounds 1-12 were activated by methylaluminoxane (MAO) and show good activity for ethylene polymerization and produced high molecular weight polyethylene.

Two Mn 6 single-molecule magnets with sulfur-contained capping ligand

The reactions of Mn(ClO 4) 2·6H 2O, 1-(2-hydroxyphenyl)ethanone oxime (abbr. as MeSao), NEt 3 and thiophene-2-carboxylic acid/thiophene-3-carboxylic acid (2-TCA/3-TCA) lead to [Mn 6O 2(MeSao) 6(2-TCA) 2(EtOH) 4(H 2O) 2](EtOH) 2 ( 1) and [Mn 6O 2(MeSao) 6(3-TCA) 2(EtOH) 4(H 2O) 2](EtOH) 2 ( 2), respectively. Their structures can be described as a core of the [Mn III 6O 2(Mesao) 6(O 2C-thiophene) 2(EtOH) 4] consisting two off-set, stacked [Mn III 3(μ 3-O 2−)] 7+ triangular subunits linked by two central oximato O-atoms and two O-atoms from phenoxide group. Magnetic investigation revealed that 1 and 2 all have a spin ground state S = 4, and both complexes show single-molecule magnet behaviors with similar energy barriers U eff ∼45 K.

Proximity effect on the general base catalysed hydrolysis of amide linkage: The role of cationic surfactant, CTABr

The bis phenoxide forms of (1,2)bis(2-hydroxybenzamido)ethane(I), (1,5)bis(2-hydroxybenzamido)3-azapentane(II), (1,3)bis(2-hydroxybenzamido)propane(III), and (1,8)bis(2-hydroxybenzamido)3,6-diazaoctane(IV) undergo facile hydrolysis of one of the amide groups (0.02 ≤ [OH − ]T (mol dm − 3) ≤ 0.5, 10% MeOH (v/v) + H2O medium) without exhibiting [OH − ] dependence. The reactivity trend follows I ~ II > > III ~ IV with low activation enthalpy {25.7 ± 2.8 ≤ ΔH≠ (kJ mol − 1) ≤ 64.8 ± 7.0}. The high negative and comparable values of activation entropy {− 234 ± 8 ≤ ΔS≠ (J K − 1 mol − 1) ≤ −127 ± 20} are consistent with closely similar, and ordered transition states which can be assembled by favourably oriented phenoxide groups. The solvent kinetic isotope effect for I, k H2O/k D2O + H2O ~1 (20 and 50 volume% D2O), indicates that proton transfer is not involved as a part of the rate controlling process. The observed slowing down of the rate of this reaction for I in the micellar pseudo phase of CTABr also supports the proposed mechanism. Under pre-micellar conditions, however, rate acceleration is observed, a consequence believed to be associated with the capping effect of the hydrophobic tail of the surfactant cation forming the reactive ion-pair, CTA + , (I-2H)2 − exclusively in the aqueous pseudo phase.

On the unprecedented level of dinitrogen activation in the calix[4]arene complex of Nb(iii)

The calix[4]arene niobium(III) complex ([L]Nb-N=N-Nb[L] where [L] = p-tert-butylcalix[4]arene), reported to bind N(2) in a μ(2)-linear dimeric capacity and to activate the N(2) triple bond to 1.39 Å, corresponding to the longest N(2) bond known in the end-on coordination mode, was subjected to a computational investigation involving both density functional and wavefunction based methods to establish the basis for the unprecedented level of activation. Replacement of the calix[4]arene ligand with hydroxide or methoxide ligands reveals that the organic backbone structure of the calix[4]arene ligand exerts negligible electronic influence over the metal centre, serving only to geometrically constrain the coordinating phenoxide groups. A fragment bonding analysis shows that metal-to-dinitrogen π* backbonding is the principal Nb-N interaction, providing a strong electronic basis for analogy with other well-characterised three- and four-coordinate complexes which bind N(2) end-on. While the calculated structure of the metallacalix[4]arene unit is reproduced with high accuracy, as is also the Nb-Nb separation, the calculated equilibrium geometry of the complex under a variety of conditions consistently indicates against a 1.39 Å activation of the N(2) bond. Instead, the calculated N-N distances fall within the range 1.26-1.30 Å, a result concordant with closely related three- and four-coordinate μ(2)-N(2) complexes as well as predictions derived from trends in N-N stretching frequency for a number of crystallographically characterized linear N(2) activators. A number of potential causes for this bond length discrepancy are explored.

(Methanol-κO)bis{2-methoxy-6-[(4-methylphenyl)iminiomethyl]phenolato-κ2O,O′}tris(nitrato-κ2O,O′)cerium(III)

The asymmetric unit of title compound, [Ce(NO3)3(C15H15NO2)2(CH3OH)], consists of two Schiff base 2-meth­oxy-6-[(4-methyl­phen­yl)iminiometh­yl]phenolate (HL) ligands, three nitrate anions and a methanol ligand. The CeIII ion is 11-coordinated: three nitrate radical anions coordinate to the CeIII ion through O atoms, two HL ligands chelate the CeIII ion through the O atoms of the phenolate and meth­oxy groups, and one methanol mol­ecule coordinates to CeIII ion through its O atom. The O atom of one nitrate anion is disordered over two sites of equal occupancy. The protonated imine N atoms are involved in intra­molecular hydrogen bonds with the phenoxide groups. C—H⋯O inter­actions are also observed.

Density Functional Analysis of the Trigonal Uranyl Equatorial Coordination in Hexahomotrioxacalix[3]arene-based Macrocyclic Complexes

Representative models of the different geometries observed for uranyl complexes with fully deprotonated p-R-hexahomotrioxacalix[3]arene (R = tert-Bu, Me) ligands, among which is the rare trigonal geometry, have been investigated using all-electron scalar relativistic density functional theory (DFT). Optimized structures of complexes incorporating triethylammonium (HNEt3+) and 4-methylpiperidinium (HMePi+) cations are in close agreement with experimental crystal diffraction data. Possible explanations for the structural differences between these uranyl complexes are discussed in terms of varying degrees of bonding between uranium and oxygen atoms from the ether and phenoxide groups. In particular, molecular orbital analysis highlights the central role of 5f-2p hybridization in the U-O bonding.

N-Heterocyclic Carbene-Catalyzed Enantioselective Mannich Reactions with α-Aryloxyacetaldehydes

N-Heterocyclic carbenes (NHCs) catalyze a new Mannich-type reaction to form beta-amino acid derivatives in high yield and enantioselectivity. The reaction is initiated by the addition of an NHC to an alpha-aryloxyaldehyde followed by elimination of a phenoxide anion which generates an enol/enolate. A Mannich addition to a tosylimine proceeds with excellent control over enantioselectivity. In a new carbene catalysis concept, catalyst regeneration is promoted by return, or rebound, and acylation of the phenoxide group which served as the activating component in the first step of the catalytic cycle. The activated ester products formed in situ are manipulated to form a variety of useful compounds including beta-amino acids, beta-amino amides, and peptides.

Synthesis, characterization, crystal structure, and theoretical studies on Schiff-base compound 6-[(5-Bromopyridin-2-yl)iminomethyl]phenol

The title Schiff-base compound, 6-[(5-Bromopyridin-2-yl)iminomethyl]phenol (1), has been synthesized and characterized by elemental analyses, FT-IR, UV–Vis and 1H-NMR spectroscopy, and X-ray single crystal diffraction. In the gas phase four isomers were found for title compound. Density functional (DFT) calculations have been carried out and it was found that the A isomer is the most stable one. The protonated imine N atom is involved in intra- and inter-molecular hydrogen bonds with the phenoxide group and H aromatic atoms, respectively. The title compound displays a trans configuration about the C=N double bond.

Tris{2-methoxy-6-[(4-methylphenyl)iminiomethyl]phenolato-κ2O,O′}tris(thiocyanato-κN)cerium(III)

The asymmetric unit of the title compound, [Ce(NCS)3(C15H15NO2)3], contains three Schiff base 2-methoxy-6-[(4-methyl­phenyl)iminometh­yl]­phenol (HL) ligands and three independent thio­cyanate ions that coordinate the cerium ion via their N atoms. The protonated imine N atoms are involved in an intra­molecular hydrogen bond with the respective phenoxide group. The Ce(III) ion exhibits a coordination number of nine.

Heterobimetallic Lanthanide/Sodium Phenoxides: Efficient Catalysts for Amidation of Aldehydes with Amines

Heterobimetallic lanthanide/sodium phenoxides were found to be efficient catalysts for amidation of aldehydes with amines under mild conditions. The reactivity follows the order Nd < Y < Sm for metals and 2,6-(Me)2C6H3O < 2,6-(iPr)2C6H3O < 2,6-(tBu)2C6H3O for phenoxide groups. In comparison with the corresponding monometallic complexes, heterobimetallic complexes show higher activity and a wider range of scope of amines. A cooperation of lanthanide and sodium in this process is proposed to contribute to the high activity of the present catalyst.

Solute-Solvent Interactions in Solutions of Solvatochromic Phenoxides: A Dynamics Simulation Study

Solute-solvent interactions in protic (water, methanol and 2-propanol) and aprotic (DMSO) solvents of four solvatochromic phenoxides, the 4- and 2-pyridiniophenoxides, Brooker’s merocyanine and the N-methyloxyquinolinium betaine, were investigated with the aid of molecular dynamics simulations. Although the size of the first solvation shell of the phenoxide oxygen of all betaines remains constant in the three protic solvents, it comprises increasingly fewer solvent molecules as the volume of the hydroxylic solvent increases. In DMSO, the donor phenoxide group of the 4-pyridiniophenoxide betaine is loosely solvated, leading to an internal charge-transfer with smaller transition energies than in protic media.

Acidity Scale for Metal Oxides and Sanderson's Electronegativities of Lanthanide Elements

Metal oxides are widely used in industry and academia. As their electron-acceptor or acidic strengths play vital roles in their applications, there needs to be a general scale that can quantitatively compare their relative acidic strengths. Conventionally, calorimetric heat measurements during adsorption of probe molecules, infrared spectroscopic analyses of adsorbed bases or acids, application of indicator dyes, and temperature-programmed desorption of the pre-adsorbed bases are standard methods for the analyses of their acidic strengths. However, these methods are not suitable for a quantitative comparison. Thus, unlike metal ions in solution, no such scales have been available for metal oxides. One of the important types of interaction between adsorbates and metal oxides is the formation of coordinate covalent bonding between adsorbates and the surface metal ions. For instance, in the case of TiO2, those compounds that have enediol, carboxylate, and nitrile groups have been shown to form coordinate covalent bonding with the surface Ti ions. In this type of interaction, the adsorbateto-metal charge-transfer interaction is often the lowestenergy electronic transition. However, in the case of alizarin (Figure 1a, inset) on TiO2, a theoretical study has suggested that the intramolecular charge-transfer (IMCT) band from the catechol moiety to the entire ring system is the lowestenergy transition. Electronegativity (EN) is one of the most important fundamental properties of an atom, which represents “the power of an atom in a compound to attract electrons to itself”. Among various EN scales that have been developed, Sanderson s scale and the associated EN equalization principle are successful in calculating the bond energies of various compounds , elucidating the acidic and basic properties of zeolites, and establishing the relationship between the reactivity and the composition of the zeolite that served as the guideline for the preparation of optimum zeolite catalysts. These methods have also been used for various other purposes. However, owing to a lack of experimental data, Sanderson s EN scale has not been extended to lanthanides (Ln) during the last five decades, despite the fact that lanthanide-containing compounds are widely used. Herein, we report that the IMCT transition of alizarin is still the lowest-energy transition when it is adsorbed on various metal oxides and sulfides, regardless of the nature of the metal ion. The charge-transfer transition serves as a highly sensitive and accurate probe for the quantitative comparison of the acidic strengths of the metal oxides and sulfides. We also report the factors that govern the surface acidity, which allows us to assign for the first time the important Sanderson s EN values of Ln ions (SLn3+) and Ce . To experimentally verify the IMCT nature of the lowestenergy electronic transition from the catechol moiety to the entire ring, we also synthesized 4-methoxyalizarin (Figure 1a, inset; Supporting Information, SI-1). The UV/Vis spectra of the two compounds (Figure 1a) show that the lowest-energy transition (2.856 eV) shifts to the lower energy region (2.617 eV) upon introducing a methoxy group at the 4 position; that is, upon increasing the donor strength of the catechol moiety, which verifies the IMCT nature of the transition. The IMCT bands of alizarin and 4-methoxyalizarin adsorbed on various metal oxides and sulfides are shown in Figure 1b, with the order of energy increasing from bottom to top. The IMCT bands appear at 2.322–2.713 eV for alizarin and 2.288–2.536 eV for 4-methoxyalizarin (Supporting Information, Table SI-2). The red-shift from alizarin to 4-methoxyalizarin also suggests that the lowest-energy transition of the adsorbed alizarin is IMCT. Furthermore, the IMCT bands of alizarin and 4-methoxyalizarin are red-shifted when they are adsorbed onto oxides and sulfides. Such coordination-induced redshifts were also observed in solution. The IMCT band of alizarin (2.398 eV) red-shifts upon coordinating to Mg in ethanol relative to its uncoordinated state (2.856 eV; Supporting Information, Figure SI-3). We attribute the red shift to a decrease in the degree of electron withdrawal of the two phenoxide groups as a result of the replacement of the two strongly electron-withdrawing protons by a less strongly electron-withdrawing metal cation (Figure 1d, inset). In this context, the gradual blue shift of the IMCT band of the adsorbed alizarin and 4-methoxyalizarin on going from MgO to Ta2O5 is attributed to the increase in the degree of electron withdrawal from the two phenoxide ligands to a surface metal ion in the following order: MgO<PbO<Y2O3<ZnO< ZnS<HfO2<Ga2O3<ZrO2<TiO2< SnO2<Ta2O5. The IMCT energies do not correlate with Sanderson s partial charges of the metal ions (dM) in metal oxides and sulfides (Figure 1c), which are expressed by Equation (1) for metal chalcogenides MxChy (Ch= chalcogen): [32] [*] N. C. Jeong, Dr. J. S. Lee, Dr. E. L. Tae, Y. J. Lee, Prof. Dr. K. B. Yoon Center for Microcrystal Assembly, Center for Nanoporous Materials, Department of Chemistry, and Program of Integrated Biotechnology, Sogang University, Seoul 121-742 (Korea) Fax: (+82)2-706-4269 E-mail: yoonkb@sogang.ac.kr

Bis{2-methoxy-6-[(4-methyl-phen-yl)iminiometh-yl]-phenolato-κO}bis-(thio-cyanato-κN)zinc(II).

The Schiff base 2-[(4-methyl­phen­yl)imino­meth­yl]-6-methoxy­phenol (HL) forms a complex with a Zn2+ atom and two independent thio­cyanate ions, [Zn(NCS)2(C15H15NO2)2], in which two phenolate O atoms the two independent Schiff base ligands are coordinated to thee Zn2+ atom. The protonated imine N atoms are involved in an intramolecular hydrogen bond with the phenoxide group. The Zn atom is also coordinated by two N atoms of two thio­cyanate ligands. The coordination environment of the Zn atom is distorted-tetra­hedral.

Bis{6-methoxy-2-[(4-methylphenyl)iminiomethyl]phenolato-κ2O,O′}bis(nitrato-κ2O,O′)cadmium(II)

The Schiff base 6-meth­oxy-2-[(4-methyl­phen­yl)imino­meth­yl]­phenol (HL) forms a neutral complex with cadmium(II) nitrate, [Cd(NO3)2(C15H15NO2)2], in which the four O atoms of the two independent ligands are coordinated to the metal center and the protonated imine N atoms are involved in a hydrogen bond with the phenoxide group. Intra­molecular N—H⋯O hydrogen-bonding inter­actions stabilize the structure. Each organic ligand assumes a zwitterionic form, chelating to the metal atom through the two O atoms, while the two nitrate groups also exhibit chelating behavior, leading to a distorted octahedral coordination of the Cd atom.

A mixed-valence copper coordination polymer generated by a hydrothermal metal/ligand redox reaction process

The title coordination polymer, poly[(mu(4)-2-oxidoisophthalato-kappa(6)O(1),O(2):O(2),O(3):O(3'):O(3'))(mu(2)-quinoxaline-kappa(2)N:N')copper(I)copper(II)], [Cu(2)(C(8)H(3)O(5))(C(8)H(6)N(2))](n), contains two crystallographically distinct Cu ions, one quinoxaline (QA) unit and one 2-oxidoisophthalate trianion (L) derived from 2-hydroxyisophthalic acid (H(3)L). The Cu(II) ion is strongly coordinated by four O atoms in a distorted square geometry, of which two belong to two phenoxide groups and the other two to carboxylate groups of two L ligands. In addition, the Cu(II) cation interacts weakly with a symmetry-related carboxylate O atom which belongs to the L ligand in an adjacent layer, giving a square-pyramidal coordination geometry. The Cu(I) ion is trigonally coordinated by two N atoms from two QA molecules and one O atom from an L carboxylate group. The Cu(I) centres are bridged by QA ligands to give a chain along the c axis. Two Cu(II) ions and two L ligands form a [Cu(2)L(2)](2-) ;metallo-ligand', which coordinates two Cu(I) ions. Thus, the chains of Cu(I) and QA are linked by the [Cu(2)L(2)](2-) metallo-ligand to yield a two-dimensional (6,3) sheet. These sheets are further linked by symmetry-related carboxylate O atoms of neighbouring layers into a three-dimensional framework. The in situ reaction from benzene-1,2,3-tricarboxylic acid (H(3)L1) to L in the present system has rarely been observed before, although a few novel in situ reactions, such as ligand oxidative coupling, hydrolysis and substitution, have been observed during the hydrothermal process.

Crosslinked Sulfonated Poly(arylene ether sulfone) Membranes as Candidate for PEMs

A series of controlled molecular weight, phenoxide-endcapped, 50% disulfonated BPS 50 copolymers was synthesized. The terminal phenoxide groups were reacted with glycidyl methacrylate via nucleophilic aromatic substitution to produce GMA-BPS 50 copolymers endcapped with crosslinkable glycidyl methacrylate moieties. Various blend compositions in varying weight percents of GMA-BPS 50-5k and 15k copolymers were made and thermally cured in presence of benzoyl peroxide initiator at 90-95 degree C. The cured copolymers were characterized in terms of water uptake,proton conductivity and self-diffusion coefficient of water.

Kinetics and mechanism of the C-S coupling reactions of aryl Grignard reagents with aryl arenesulfonates

Abstract The kinetics of the C-S coupling of arylmagnesium bromides with phenyl tosylate has been studied in THF: toluene at 90°C. The reaction is first order in Grignard reagent and first order in phenyl tosylate. Kinetic data, Hammett relationship and activation parameters are consistent with a nucleophilic addition mechanism involving rate determining attack of carbanion to sulfonyl group followed by a fast phenoxide group leaving.

Coordination Versatility of 5(3)‐(2‐Hydroxyphenyl)‐3(5)‐methylpyrazole: Synthesis, Crystal Structure and Properties of CoIII, NiII and CuII Complexes

AbstractNew complexes with 5(3)‐(2‐hydroxyphenyl)‐3(5)‐methylpyrazole (H2phpz), [Co2(H2phpz)(Hphpz)2(phpz)2]·3CH3CN (1), [Ni(Hphpz)2] (2) and [Cu(Hphpz)2] (3), were synthesized and structurally characterized. The ligand coordinates in the form of 3‐(2‐hydroxyphenyl)‐5‐methylpyrazole in all cases, except for one ligand in the CoIII complex, where it coordinates in the 5‐(2‐hydroxyphenyl)‐3‐methylpyrazole mode. Crystallographic analysis revealed that 1 contains two chemically and crystallographically distinct cobalt(III) ions triply bridged by one phenoxide and two pyrazolate groups, giving rise to a [Co2(N‐N)2O] core with a Co···Co distance of 3.154 Å. Additionally, the H2phpz ligand shows four different coordination modes with the metal ions, demonstrating its versatility. The dinuclear unit of 1 is stabilized by strong intramolecular N–H···O hydrogen‐bonding interactions involving the phenol oxygen atom of the H2phpz ligand and the N–H functionality of the pyrazole ring. The crystal structure of the isomorphous complexes 2 and 3 reveals the presence of centrosymmetric mononuclear units with the MN2O2 [M = NiII (2), CuII (3)] chromophore displaying a slightly distorted square‐planar geometry. The mononuclear structures of 2 and 3 are further stabilized by intramolecular hydrogen bonds established between the acid N–H group as donor and the phenoxide group of the H2phpz ligand as acceptor. Spectroscopic studies, ESI‐MS and cyclic voltammetry were performed, supporting the crystallographic analysis. (© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2007)

2,2′-Iminobis(ethanaminium) (p-methyldihomooxacalix[4]arene)dioxouranium methanol disolvate monohydrate

In the title compound, (C4H15N3)[UO2(C33H30O5)]·2CH3OH·H2O, the uranyl ion is bound to the four phenoxide groups of the deprotonated p-methyl­dihomooxacalix[4]arene in the usual cone conformation, giving a dianionic complex. The diprotonated diethyl­enetriamine counter-ion links neighbouring complex anions along the b axis through hydrogen bonding with the oxo, phenoxide and ether groups. The solvent mol­ecules are also involved in hydrogen bonding.