Naphthalene System Research Articles

Benchmarking the CO2 Adsorption Energy on Carbon Nanotubes

We present benchmark interaction energy calculations of carbon dioxide physisorbed onto flat and curved polycyclic aromatic hydrocarbons as models of carbon nanotubes. The accuracy of the complete-basis-set second-order Møller–Plesset perturbation theory combined with a CCSD(T) coupled-cluster correction in a moderate basis set is first assessed for a series of CO2–(benzene, naphthalene, and pyrene) complexes to establish the basis set requirements. The same composite approach is then used to compute accurate interaction energies for 195 CO2–curved coronene geometries representing different intermolecular distances, orientations, and nanotube diameters. The CO2–curved coronene benchmark data set is then used to assess the performance of a wide variety of dispersion-including DFT functionals. Among them, only the nonlocal VV10 and double-hybrid B2PLYP-D3(BJ) functionals exhibit relative errors below 10%. Interestingly, all DFT variants deviate strongly from the benchmark at short-range because of overdamping. We show that these short-range deficiencies can be corrected by refitting the damping parameters of Grimme’s -D3 dispersion approach on the newly constructed data set and that the refitted parameters are also suitable for the complexes of CO2 with larger polycyclic aromatic hydrocarbons but not for the smaller CO2–benzene and CO2–naphthalene systems.

Crystal structure of 4-bromo-N-(2-bromo-3-nitro-benz-yl)-2-nitro-naphthalen-1-amine.

In the title compound, C17H11Br2N3O4, the dihedral angle between the planes of the naphthalene system and the benzene ring is 52.86 (8)°. The nitro substituent and the attached naphthalene system are almost coplanar [dihedral angle = 5.6 (4)°], probably as a consequence of an intra­molecular N—H⋯O hydrogen bond with the amine group. The nitro substituent attached to the benzene ring is disordered over two sets of sites with occupancies of 0.694 (3) and 0.306 (3). The major component deviates significantly from the ring plane [dihedral angle = 53.6 (2)°]. In the crystal, the mol­ecules are linked into a three-dimensional array by extensive π–π inter­actions involving both the naphthalene and benzene rings [range of centroid–centroid distances = 3.5295 (16)–3.9629 (18) Å] and C—H⋯O inter­actions involving the methyl­ene H atoms and the phenyl-attached nitro group.

Platinum bisphosphine complexes of 1,8-naphthosultone

A series of three platinum(II) bisphosphine complexes 1–3 [Pt(1-(SO2),8-(O)-nap)(PR3)2] (where R3=Ph3, Ph2Me, Me2Ph) have been prepared by metathesis from cis-[Pt(PR3)2Cl2)] and the dilithium salt of 1,8-naphthosultone. The novel compounds were fully characterised by X-ray crystallography, multinuclear NMR, IR and MS. The molecular structures of 1–3 were compared by measuring the peri-distance, splay angle magnitude, peri-atom displacement, naphthalene ring torsions, aromatic ring orientations and the geometry around the platinum centre. The platinum metal adopts a distorted square planar geometry in all three complexes which causes deformation of the naphthalene system. The degree of molecular deformation does not decrease upon going from 1 to 3 as anticipated, instead a competition between steric effects and intramolecular interactions causes 3 to display distortion intermediate of 1 and 2.

An efficient ligand-free ferric chloride catalyzed synthesis of annulated 1,4-thiazine-3-one derivatives

A straight forward route for the synthesis of coumarin-, quinolone-annulated 1,4-thiazine-3-one derivatives has been achieved by using sodium sulfide as the sulfur source and ferric chloride as catalyst in a ligand-free condition. The synthetic procedure is simple, inexpensive, and affords the products in good yields. This methodology is also applicable to naphthalene and benzene systems.

Batch equilibrium and kinetic studies of naphthalene and pyrene adsorption onto coconut shell as low-cost adsorbent

This study investigated the use of coconut shell as a non-conventional and low-cost adsorbent for the removal of naphthalene and pyrene from synthetic waste water. Coconut shells were used to adsorb naphthalene and pyrene at varying initial naphthalene and pyrene concentrations, adsorbent dosage, particle size and agitation time. The results of the batch equilibrium adsorption studies revealed that adsorption capacity decreased with increase in particle size and increased with increase in adsorbent dosage. The equilibrium adsorption data were analysed by two-parameter models of Langmuir and Freundlich and three-parameter models of Redlich-Peterson, Sips and Toth isotherms. The results showed that the equilibrium adsorption data for naphthalene and pyrene sorbent systems fitted well with all the tested adsorption isotherm models which can adequately describe the adsorption behaviour of naphthalene and pyrene onto coconut shell. The adsorption kinetic data obtained at 100 mg/l initial naphthalene and pyrene concentrations were analysed using Lagergren pseudo-first order, Elovich and intraparticle diffusion rate equations. The rate equations fitting showed that the adsorption kinetic data generally fit the three rate equations tested from which the rate constants and diffusion rate constants were estimated. However, the Lagergren pseudo first-order rate equation gave the best fit and, thus the process followed the first-order rate kinetics. Therefore, coconut shells being an agricultural waste product have the potential to be used as a low-cost adsorbent for the removal of organic pollutant from waste water.

2,7-Dihydroxy-8-(4-phenoxybenzoyl)naphthalen-1-yl](4-phenoxyphenyl)methanone

In the title compound, C36H24O6, the benzoyl groups at the 1- and 8-positions of the naphthalene system are in an anti orientation. Both carbonyl groups form intra­molecular O—H⋯O hydrogen bonds with hy­droxy groups affording six-membered rings. The benzene rings of the benzoyl groups make dihedral angles of 59.26 (13) and 59.09 (13)° with the naphthalene ring system. Zigzag C—H⋯O chains and ladder C—H⋯O chains between the phenoxybenzoyl groups along the ab diagonals form an undulating checkered sheet. The molecules are further connected into a three-dimensional network by C—H⋯π interactions.

4-Hydroxymethyl-10-methoxy-17,22-dioxapentacyclo[21.2.2.213,16.13,7.011,30]triaconta-1(25),3,5,7(30),8,10,13,15,23,26,28-undecaene-2,12-dione acetone monosolvate

In the title compound, C30H26O6·C3H6O, the syn-oriented benzoyl groups are nearly parallel to each other; the dihedral angle between their benzene rings is 15.9 (1)°. They form dihedral angles of 72.5 (1) and 84.3 (1)° with the naphthalene system. In the crystal, mol­ecules are linked into a three-dimensional architecture by C—H⋯O and C—H⋯π inter­actions.

2,7-Dimethoxy-1-(2-naphthoyl)naphthalene

In the title mol­ecule, C23H18O3, the dihedral angle between the two naphthalene ring systems is 80.44 (4)°. The mean plane of the bridging carbonyl C—C(=O)—C group makes a torsion angle of −68.55 (17)° with the naphthalene system of the 2,7-dimeth­oxy­naphthalene unit and a torsion angle of −9.01 (19)° with the naphthalene ring system of the naphthoyl group. In the crystal, a weak C—H⋯O hydrogen bond occurs between the carbonyl O atom and an H atom of the naphthalene ring in the 2,7-dimeth­oxy­naphthalene unit of a symmetry-related mol­ecule.

Alkaline earth metal salts of 1-naphthoic acid

The structures of the Mg, Ca, Sr and Ba salts of 1-naphthoic acid are examined and compared with analogous structures of salts of benzoate derivatives. It is shown that catena-poly[[[diaquabis(1-naphthoato-κO)magnesium(II)]-μ-aqua] dihydrate], {[Mg(C(11)H(7)O(2))(2)(H(2)O)(3)]·2H(2)O}(n), exists as a one-dimensional coordination polymer that propagates only through Mg-OH(2)-Mg interactions along the crystallographic b direction. In contrast with related benzoate salts, the naphthalene systems are large enough to prevent inorganic chain-to-chain interactions, and thus species with inorganic channels rather than layers are formed. The Ca, Sr and Ba salts all have metal centres that lie on a twofold axis (Z' = 1/2) and all have the common name catena-poly[[diaquametal(II)]-bis(μ-1-naphthoato)-κ(3)O,O':O;κ(3)O:O,O'], [M(C(11)H(7)O(2))(2)(H(2)O)(2)](n), where M = Ca, Sr or Ba. The Ca and Sr salts are essentially isostructural, and all three species form one-dimensional coordination polymers through a carboxylate group that forms three M-O bonds. The polymeric chains propagate via c-glide planes and through MOMO four-membered rings. Again, inorganic channel structures are formed rather than layered structures, and the three structures are similar to those found for Ca and Sr salicylates and other substituted benzoates.

1-(Phenylsulfonyl)naphthalene

In the title compound, C16H12O2S, the phenyl ring is nearly perpendicular to the naphthalene system [dihedral angle = 80.3 (1)°]. The packing is consolidated by a weak C—H⋯π inter­action involving neighbouring naphthalene and benzene rings. In addition, there exist two different offset π–π stacking inter­actions between benzene rings and between naphthalene systems of symmetry-related mol­ecules [centroid–centroid distances = 3.876 (9) and 3.566 (4) Å, and slippage = 1.412 and 0.554 Å, respectively.

N-Benzoyl-N-(1,4-dioxonaphthalen-2-yl)benzamide.

The title mol­ecule, C24H15NO4, crystallizes with two mol­ecules in the asymmetric unit (Z′ = 2). For both mol­ecules, the two amide groups are not coplanar, as the dihedral angles of the respective NCO groups are similar at 50.37 (14) and 51.22 (13)°. However, the orientations of the substituent phenyl rings with the central naphthalene system are significantly different for the two mol­ecules; for one mol­ecule, these dihedral angles are 80.29 (3) and 80.95 (4)°, while for the second mol­ecule they are 86.63 (3) and 72.82 (4)°. The crystal packing shows the mol­ecules to be linked by weak C—H⋯O inter­actions.

Theoretical Prediction of Triplet–Triplet Energy Transfer Rates in a Benzophenone–Fluorene–Naphthalene System

Triplet–triplet energy transfer in benzophenone–fluorene and benzophenone–fluorene–naphthalene molecules is theoretically investigated by using the rate theories and electronic structure calculations established for electron transfer. From the calculated electronic couplings for the single-step tunneling and multistep hopping pathways of the energy transfer from the donor benzophenone to the acceptor naphthalene, it is found that the tunneling comes from the direct electronic couplings between the donor and acceptor states, other than the coupling via the virtual bridge state in the conventional superexchange mechanism. The mode-specific reorganization energy calculations reveal that only the several high-frequency modes dominate the energy transfer, leading to an important nuclear tunneling effect. Succeedingly, with use of the obtained parameters, Fermi’s golden rule predicts the consistent energy transfer rates with experimental ones.

Regioselective iridium(I)-catalysed remote borylation of oxygenated naphthalenes

We present our investigations into the regioselective borylation and halogenation of polyoxygenated naphthalene systems that are key precursors to dimeric pyranonaphthoquinone natural products. A variety of oxygenated naphthalenes were successfully borylated with pinacolborane in high yield and excellent regioselectivity using [Ir(COD)OMe]2 and di-tert-butylbipyridine (dtbpy). The boronates were also readily transformed into the corresponding halides, opening new avenues for the preparation of advanced Suzuki coupling substrates useful for the synthesis of natural products.

N-(2-{[7-(2-Anilinoethoxy)-3,6-dibromonaphthalen-2-yl]oxy}ethyl)aniline

In the title compound, C26H24Br2N2O2, the central naphthalene system carries two Br atoms and two –CH2CH2NHC6H5 substituents. The phenyl rings of the latter residues are inclined at 74.17 (17) and 51.4 (2)° with respect to the naphthalene ring system. Each alkyl chain adopts a fully extended all-cis conformation with respect to the naphthalene and phenyl rings [N—C—C—O torsion angles = 68.6 (4) and 60.5 (4)°]. In the crystal, one of the N—H groups forms bifurcated N—H⋯(Br,O) hydrogen bonds, which link the mol­ecules into inversion-related dimers. The centrosymmetric dimers are aggregated via pairs of C—H⋯π inter­actions into sheets parallel to (110).

Simple Tuning of the Optoelectronic Properties of IrIII and PtII Electrophosphors Based on Linkage Isomer Formation with a Naphthylthiazolyl Moiety

AbstractBy tuning the substitution position of a thiazolyl group on the naphthalene system (α or β site), the distinctive electronic structures associated with these functional ligands have a substantial influence on both the photophysical behavior and electroluminescent (EL) performance of the resulting linkage isomers for two series of IrIII and PtII phosphorescent emitters. The photoluminescence wavelength can be redshifted by ca. 23 nm for the linkage isomers upon replacing the β‐substituted thiazolyl‐based ligand with its α‐substituted counterpart in the homoleptic series of IrIII phosphors. Furthermore, the bathochromic effect can be as much as ca. 42 nm for the heteroleptic IrIII phosphors and ca. 59 nm for the PtII compounds. Similarly, metallophosphors that bear β‐substituted ligands exhibit a different EL performance with respect to that of their linkage isomers with α‐substituted ligands. The best EL results associated with the triplet emitters chelated with β‐substituted ligands show a maximum brightness (Lmax) of 22563 cd m–2, an external quantum efficiency (ηext) of 12.88 %, a luminance efficiency (ηL) of 30.84 cd A–1, and a power efficiency (ηp) of 26.17 lm W–1, whereas the EL performance of their α‐counterparts was characterized by a peak Lmax of 8653 cd m–2, ηext of 6.18 %, ηL of 8.55 cd A–1, and ηp of 6.54 lm W–1. Owing to its unique electronic structure, the thiazolyl group is a good alternative to the pyridyl moiety to improve the EL performance of the metallophosphor. We have also demonstrated a simple and useful route to tune the functional properties of cyclometalated triplet emitters for EL applications.

2-[(E)-(Naphthalen-2-ylimino)methyl]-4-(trifluoromethoxy)phenol

In the title compound, C18H12F3NO2, the planes of the benzene ring and the naphthalene system form a dihedral angle of 47.21 (3)°. The hy­droxy group is involved in an intra­molecular O—H⋯N hydrogen bond. In the crystal, weak C—H⋯O and C—H⋯F inter­actions link the mol­ecules related by translations along the c and a axes, respectively, into sheets.

1-[(4-Bromophenyl)(morpholin-4-yl)methyl]naphthalen-2-ol

The title compound, C21H20BrNO2, was obtained via a one-pot synthesis from the reaction of 4-bromo­benzaldehyde, 2-naphthol and morpholine. In the asymmetric unit, there are four mol­ecules with similar structures. The morpholine ring adopts a chair conformation, and the hy­droxy group links with the morpholine via an intra­molecular O—H⋯N hydrogen bond. The bromo­phenyl ring is approximately perpendicular to the mean pane of the naphthalene system at dihedral angles of 76.7 (3), 81.4 (3), 79.7 (3) and 84.5 (3)° in the four independent mol­ecules. Weak C—H⋯O hydrogen bonds are observed in the crystal.

(3-Ethyl-6,7-dimethoxynaphthalen-1-yl)(phenyl)methanone

The asymetric unit of the title mol­ecule, C21H20O3, contains two crystallographically independent mol­ecules, A and B, which differ in the orientation of the ethyl group substituted on the naphthalene system; the dihedral angles between the ethyl group and the naphthalene system are 7.4 (3) and 68.1 (3)°, respectively, for mol­ecules A and B. The dihedral angles between the benzoyl and naphthalene groups are 64.7 (7) and 69.4 (8)°, respectively, for mol­ecules A and B. The crystal structure features four aromatic π–π stacking interactions [centroid–centroid distances = 4.181 (1), 3.891 (1), 4.423 (1) and 4.249 (1) Å].

A theoretical investigation on the effect of π–π stacking interaction on 1H isotropic chemical shielding in certain homo- and hetero-nuclear aromatic systems

Significant changes in the proton chemical shielding (and hence the chemical shift) are predicted in going from the monomer to the dimer of benzene, naphthalene, pyridine and quinoline systems and also the trimer of benzene and pyridine. The computed NMR spectra show additional splitting in going from the monomer to the dimer and the trimer of different species. The aromatic protons show a significant upfield shift due to the enhancement of anisotropic shielding by the π electron cloud of the neighboring molecule(s). The nature of the NMR spectra also changes with the orientation of the stacked conformers. The results obtained using Moller-Plesset second-order perturbation theory along with the GIAO method show the changes in isotropic shielding, in a reasonable basis set independent fashion.

Theoretical investigation of thermally and photochemically induced haptotropic rearrangements of chromium ligands on naphthalene systems

The description of chemical reactions by means of quantum mechanical methods is an important task and gets even more challenging if excited states have to be considered. This work focuses on the haptotropic rearrangements of chromium atoms bearing three coligands which migrate on a naphthalene-like system. The reactions are either thermally or photochemically controllable and thus the systems are candidates for molecular switches. We propose a detailed reaction scheme for the investigated system. Furthermore, we provide a detailed analysis of the important steps of the reaction cycle. In comparison to previous publications, the scope of this work also involves the quantum mechanical treatment of excited states in order to describe occurring photon absorption processes in a proper way. Linear response time-dependent density functional theory calculations were carried out to describe the molecules’ responses to the external electromagnetic perturbations.