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The literary data concerning preparation methods and spectral properties of cyclocondensation products of 1,8-naphthalic anhydrides with aromatic and aliphatic 1,2-diamines and their use as luminescent materials have been summarized. The reaction of 1,8-naphthalic anhydrides with ortho-phenylenediamine results in the formation of 1,8-naphthoylene-1’,2’-benzimidazoles, which are widely used as materials for luminescent flaw detection, for synthesis of polymers with luminescent color, in organic light emitting diodes, as luminescent sensors for cations of various metals. Moreover, their cytotoxic activity is studied in relation to cells of various tumors. Acenaphthoquinone or 8-formyl-1-naphthoic acid can also be used as starting materials for synthesis of 1,8-naphthoylene-1’,2’-benzimidazoles. The spectral properties of 1,8-naphthoylene-1’,2’-benzimidazoles can be varied by the substituent introduction to naphthalene or/and phenyl moieties leading to luminescent materials with blue, green-yellow or red luminescence. Reaction of 4-substituted naphthalic anhydrides with o-phenylenediamine results in mixture of two constitutional isomers due to nonequivalence of two carbonyl groups in starting anhydride. The isomer ratio remains unchanged provided that syntheses are carried out under the same conditions, therefore the luminescent properties of such isomer mixtures are constant. 1,8-Naphthoylene-1’,2’-benzimidazoles with electron donating groups in positions 4 or 5 of naphthalene ring can be successfully obtained by nucleophilic aromatic substitution of halogen by amine or alcoholate. The introduction of electron donating substituents to positions 4 or 5 of naphthalene ring results in bathochromic shift of absorption and emission maxima compared to unsubstituted 1,8-naphthoylene-1’,2’-benzimidazole, corresponding shift is 10-20 nm larger for 5-isomer than for 4-isomer. There are few examples of applying amines other than o-phenylenediamine for cyclocondensation with naphthalic anhydrides, for instance naphthalene-2,3-diamine and ethylenediamine were used as starting materials., Систематизовані літературні дані про методи отримання та спектральні властивості продуктів циклоконденсації нафталевих ангідридів з ароматичними та аліфатичними 1,2-діамінами та про їх застосування як люмінесцентних матеріалів.

International audience; The design of photoinitiators of polymerization is an active research field and the development of initiators activable in the visible range and under low light intensity have been the focus of numerous research efforts from both the academic and industrial communities. Recently, two families of polyaromatic compounds, i.e. 1,8-naphthalic anhydride and naphthalimides, have been extensively studied by different research groups due to their easiness of synthesis and the possibility to easily tune the photophysical properties. Especially, panchromatic, crosslinkable or water-soluble photoinitiators could be easily developed starting from the benchmark and cheap 1,8-naphthalic anhydride. In this review, an overview of the different photoinitiators based on naphthalic anhydride or the naphthalimide scaffold is presented. Based on the diversity of structures reported in the literature, a structure-performance relationship could be established in this review.

The tailored synthesis of homo (A2) and hetero (AB) N-substituted peri-xanthenoxanthene diimides (PXXDIs) and peri-functionalized PXX monoimides (PXXMIs) from 3-hydroxy naphthalic anhydride is described. As A2-type PXXDIs could be synthesized in one step, AB-type PXXDIs and PXXMIs were prepared through a modular approach capitalizing on sequential Suzuki coupling, imidation, and Pummerer reactions with very high yields. In view of their potential applications as organic semiconductors, self-organization studies were performed through liquid deposition on surfaces, depicting the formation of islands, needles, and rods.

The compound of (4-hydroxy-3-nitro-1,8-naphthalic anhydride) and the dopant material (4-hydroxy-m-benzene-disulfonic acid) were synthesized. The UV-Vis absorption and fluorescence spectra of the compound were recorded. The bathochromic shifts in absorption due to the changes in the solvent polarity was observed, in DMSO solvent, the compound shows different peaks, three bands in the UV region and one band in the visible region, one absorption peak at 402 nm, which might be attributed to the (ICT) band. The emission spectra of this compound were sensitive to the solvent polarity. They moved to lower energies with increasing the polarity of the solvent. The influence of the solvent polarity on the fluorescence maximum was more pronounced compared with the absorption maximum, showing ca. 3 nm red shift on moving from butanol to DMSO. The effect of the dopant material on the conductivities (ionic and specific) of the compound was studied, the ionic conductivity was increased as the weight of the dopant material increases, and the ionic conductivity (G) was measured in water as a solvent. the (G) of the compound was 2.4X10-6Siemens at 0.01 gm of the dopant material, and was 2.62X10-4Siemens after the dopant material was added (0.1 gm).

Glycosides and acyl glycosides of phenylphenalenones, phenylbenzoisochromenones, and structurally related natural products from plants are compiled. With the exception of one naphthalic anhydride glucoside from the Musaceae, all glycosides are chemotaxonomic markers of the Haemodoraceae, subfamily Haemodoroideae. NMR spectroscopic data indicate that in 6- O -glycosides of phenylphenalenones and phenylbenzoisochromenones, the substituents at C-5 and C-7 impede rotation of the interjacent sugar moiety at C-6. Furthermore, the structure of the acyl substituent at the C-6” hydroxyl group of some glucosides, previously reported as an allophanyl unit, in this review has been revised to a malonyl unit.

The modular synthesis of asymmetric rylenes from naphthalic anhydride derivatives is presented. Imidization, Suzuki–Miyaura coupling and cyclodehydrogenation reactions are utilized for the generation of novel functional rylenes with these three core transformations providing significant flexibility over the final structure. The combination of simple purification and high yields enables access to asymmetric rylenes with functional handles at the imide-position and site-specific incorporation of bay position substituents. The resulting library of perylenes and bisnapthalimide-anthracene derivatives showcase the presented methodology and the ability to tune optoelectronic and electrochemical properties.

A diarylethene molecule consisting of an 1,8-naphthalic anhydride and two 2,5 dimethylthiophene which exhibits reversible fluorescence switching capacity as well as solvatochromism with red shift of the fluorescence maximum by more than 150 nm.

New N-carboxyethyl-1,8-naphthalimides with fragments of morpholine and piperidine in positions 4 and 5 of naphthalene ring were synthesized by acylation of β-alanine with 4,5-dimorpholino- and 4,5-dipiperidino-1,8-naphthalic anhydrides in acetic acid. Corresponding 4,5-disubstituted naphthalic anhydrides were obtained by nucleophilic substitution of chlorine atoms in 4,5-dichloro-1,8-naphthalic anhydride on corresponding electron donating amino substitutients using dimethyl sulfoxide as solvent. Starting 4,5-dichloro-1,8-naphthalic anhydride was obtained by oxidation of 4,5-disubstituted acenaphthene with sodium dichromate in acetic acid. The same sequence of reactions can not be used for synthesis of N-carboxyethyl-1,8-naphthalimides with 2-hydroxyethylamino groups in positions 4 and 5 as the main product of reaction of 4,5-dichloro-1,8-naphthalic anhydride with ethanolamine is the product of nucleophilic addition of primary amine to carbonyl group of anhydride cycle but not the product of chlorine atoms substitution. Thus N-carboxyethyl-4,5-di(2-hydroxyethylamino)-1,8-naphthalimide was obtained by acylation of β-alanine with 4,5-dichloro-1,8-naphthalic anhydride followed by chlorine atoms substitution in N-carboxyethyl-4,5-dichloro-1,8- naphthalimide. The synthesized N-carboxyethylnaphthalimides with morpholino-, piperidino and 2-hydroxyethylamino groups in positions 4 and 5 are orange crystal substances with yellow fluorescence. Their structure was confirmed by IR and NMR 1H spectroscopy. The obtained fluorophores have weak fluorescence in aqueous solutions but their fluorescence increases 14-22 times by addition of albumin, so they can be considered as perspective substances for their further research as fluorescent probes for proteins., Синтезовано N-карбоксиетилнафталіміди з залишками морфоліну та піперидину в положеннях 4 та 5 ацилуванням β-аланіну 4,5-диморфоліно- та 4,5-дипіперидинонафталевими ангідридами. N-карбоксиетилнафталіміди з залишками етаноламіну в положеннях 4 та 5 отримано ацилуванням β-аланіну 4,5-дихлоронафталевим ангідридом з подальшим заміщенням атомів хлору на 2-гідроксиетиламіногрупи. Показано, що інтенсивність флуоресценції синтезованих сполук у водному розчині альбуміну значно збільшується в порівнянні з водою, що дозволяє вважати ці речовини перспективними для використання як флуоресцентних зондів.

The present study aimed at alleviating the impacts of alachlor (Ala) or atrazine (Atr) on maize growth by seed-dressing with naphthalic anhydride (NA, 0.4% w/w by seed weight). The dressed and undressed seeds were germinated for 10 days and treated with Ala or Atr at 3.2 or 1.8 kg ha−1, respectively, then the herbicide residues were determined in shoots one day after treatment. Atr residues were higher than Ala and remained in the same level for the 2nd day then retracted consistently up to 12 days. Meanwhile, GSH and GST were significantly induced while growth parameters were reduced; the effect of Atr was higher than Ala. Nonetheless, ABA, phenolics and anthocyanins as well as PAL, TAL and CI were increased but IAA was decreased coincidently with enhanced IAA-O and peroxidase. The immediate detection of the herbicide residues could conclude that growth reduction as elucidated from the decreased IAA concomitant with elevating ABA, phenolics and anthocyanin contents and enzyme activities are consequences of the herbicide persistence. The drop of IAA was preceded by the stimulation of IAA-O and peroxidase while the increased phenolics and anthocyanins followed PAL, TAL and CI stimulation confirming the regulatory roles of these enzymes. The application of NA greatly lowered the herbicide residues concurrently with ameliorations in growth parameters, GSH, GST, and maintained the balancing of secondary metabolites and plant growth regulators. Lowering Ala and Atr residues by NA in synchronization with enhanced GSH and GST could conclude that NA encouraged the detoxification of the herbicide. Moreover, the balances of IAA, ABA, phenolics and anthocyanins were mostly maintained in normal levels concomitantly with growth ameliorations suggesting that phytohormones and secondary metabolites are involved in the elevation of maize tolerance to Ala and Atr., Maize; Naphthalic Anhydride; Herbicides; Persistence; tolerance; Agricultural Science; Agricultural Policy; Agronomy; Environmental Science; Plant Biology.

A series of highly fluorescent polysilsesquioxane materials based on 1,8-naphthalic anhydride derivatives(XNA) have been prepared. The XNAs were chemically bonded with the polysiloxane. Though the fluorescent intensities of the solution of XNAs with different substitutes make a great difference, some of them are even very weakly emissive, the fluorescent intensities of the corresponding solid polysilsesquioxane materials are strong. In this case, the electronic effect of the substitute became non-important. With restricted molecular motion and J-aggregation, some traditionally weakly fluorescent or non-fluorescent chromophoric organics due to the substituent effect may be used to prepare highly fluorescent materials.

Room temperature phosphorescence (RTP) emission was achieved by host–guest recognition between γ-cyclodextrin (γ-CD) and a 4-bromo-1,8-naphthalic anhydride (BrNpA) polymer (poly-BrNpA), which can be controlled by the photo-isomerization of the azobenzene (Azo) unit of the other polymer (poly-Azo) in aqueous solution.

Two groups of new naphthalene-1,8-dicarboxylic acid derived compounds, 6-amino-1,8-naphthalic anhydride derivatives and 2-hydroxy-6-amino-1,8-naphthalimide derivatives, have been synthesized and characterized. The spectroscopic properties of all synthesized compounds were investigated in order to be used in the field of bio-imaging studies and as intermediates for the preparation of new fluorescent bioactive compounds. Positive solvatochromism was observed from non-polar to polar solvents and it was discussed using Catalan multilinear regression analysis. Comparative study of the photophysical characteristics of naphthalic anhydride and 1,8-naphthalimide derivatives was performed. The new naphthalic anhydride 6-(4-benzyl-piperazin-1-yl)benzo[de]isochromene-1,3-dione (3) presents the highest value of fluorescence quantum yield in solvents with lower polarities. The results demonstrate that the quantum yields values of naphthalic anhydride derivatives are higher than those of naphthalimide derivatives.

A resistência não relacionada ao local de ação (NRLA) pelo incremento da degradação de herbicidas é um problema crescente em várias espécies ao redor do mundo. Neste estudo foi avaliada a ocorrência de incremento da degradação por enzimas citocromo P450 monoxigenases (cytP450) como mecanismo de resistência ao imazethapyr em capim-arroz. Os inibidores de cytP450 malathion e butóxido de piperonila (PBO) e o indutor anidrido naftálico (AN), aplicados em mistura ou sequencialmente ao imazethapyr, foram avaliados sobre biótipos de capim-arroz suscetíveis e resistentes às imidazolinonasàs imidazolinonas . Além disso, a degradação de imazethapyr foi analisada em plantas tratadas com esse herbicida, aplicado isoladamente ou duas horas após malathion ou AN. A pulverização de malathion e PBO reduziu o fator de resistência (FR) de 15,92 para 3,44 e 4,99, respectivamente, na população resistente PALMS01. Inversamente, o indutor de cytP450 AN aumentou o FR de 4,45 para 8,32. A pulverização prévia de malathion aumentou a concentração de imazethapyr em plantas de capimarroz resistentes, em comparação com plantas que receberam apenas o herbicida, indicando a inibição da degradação de imazethapyr. A pulverização simultânea de malathion e imazethapyr foi menos eficiente que a aplicação prévia deste inibidor de cytP450. Esses resultados indicam que o incremento de metabolização causado por enzimas cytP450 está envolvido no mecanismo de resistência de capim-arroz ao imazethapyr, e medidas apropriadas devem ser tomadas para manejar essas populações. Non-target site (NTS) herbicide resistance by degradation enhancement is an increasing problem in several weeds around the world. In this study, the occurrence of degradation enhancement by cytochrome P450 monooxygenases (cytP450) was evaluated as the mechanism of resistance to imazethapyr in barnyardgrass. The cytP450 inhibitors malathion and piperonyl butoxide (PBO) and the inducer naphthalic anhydride (NA), applied in mixture or sequentially with imazethapyr, were evaluated on imidazolinone-susceptible and – resistant barnyardgrass byotipes. In addition, the degradation of imazethapyr was analyzed in plants treated with imazethapyr applied alone or two hours after malathion or NA. The spraying of malathion and PBO reduced the resistance factor (RF) from 15.92 to 3.44 and 4.99, respectively, in the resistant population PALMS01. Conversely, the cytP450 inducer NA increased the RF from 4.45 to 8.32. Malathion increased imazethapyr concentrations in resistant barnyardgrass in comparison with plants sprayed with the herbicide alone, indicating the inhibition of imazethapyr degradation. The simultaneous spraying of malathion and imazethapyr was less efficient than the previous application of this cytP450 inhibitor. These results indicate that degradation enhancement caused by cytP450 enzymes is involved in the resistance mechanism of barnyardgrass to imazethapyr, and appropriate measures should be taken to manage these populations.

The tetraoctylammonium salts of 4,5-dichloro-1,8-naphthalimide, 4,5-dibromo-1,8-naphthalimide, 4,5-dinitro-1,8-naphthalimide and 4-bromo-5-nitro-1,8-naphthalimide were synthesized with high yields of 93-96 %. The synthesis was performed with corresponding 4,5-disubstituted 1,8-naphthalimides and tetraoctylammonium iodide as starting materials in two-phase system “benzene – 5% NaOH aqueous solution” at room temperature by anion exchange and subsequent extraction of the desired salts into organic phase. Starting 4,5-dichloro-, 4,5-dibromo-, 4,5-dinitro- and 4-bromo-5-nitro-1,8-naphthalimides were obtained by oxidation of 4,5-disubstituted acenaphthenes and further acylation of ammonia by corresponding 4,5-disubstituted naphthalic anhydrides. The structures of the synthesized tetraoctylammonium salts of 4,5-disubstituted 1,8-naphthalimides were confirmed by IR and NMR 1Н spectroscopy. It was observed that signals of aromatic protons of tetraoctylammonium salts are situated in NMR 1H spectra in stronger field in comparison with corresponding 4,5-disubstituted naphthalimides. Furthermore, the valence vibration band of NH bond is absent in IR spectra of obtained tetraoctylammonium salts, while the band of imide carbonyl group is shifted to the low frequency region comparing to corresponding 4,5-disubstituted naphthalimides. The obtained tetraoctylammonium salts of 4,5-disubstituted naphthalimides are soluble in nonpolar organic solvents, for example in benzene and toluene, unlike the corresponding naphthalimides. The ability of tetraoctylammonium salts of 4,5-disubstituted naphthalimides to be effective donors of 4,5-disubstituted 1,8-naphthalimide fragment in mild conditions was shown. The proposed method for the synthesis of functional derivatives of 4,5-disubstituted naphthalimides, based on the alkylation reactions of tetraalkylammonium salts, has a number of synthetic advantages in comparison with the method of acylation of primary amines with naphthalic anhydrides and the method of phase-transfer catalytic alkylation of naphthalimides., Синтезовано ряд тетраоктиламонійних солей 4,5-дизаміщених нафталімідів, які є зручними донорами 4,5-дизаміщеного нафталімідного фрагменту в м’яких умовах.

Glasshouse research was conducted to investigate the efficacy of herbicide safeners for improving creeping bentgrass (CBG) tolerance to various herbicides. CBG injury from amicarbazone (150 g ha−1), bispyribac-sodium (110 g ha−1), fenoxaprop-p-ethyl (35 g ha−1), imazapic (45 g ha−1), quinclorac (1,050 g ha−1), or topramezone (37 g ha−1) applied in combination with the herbicide safeners naphthalic anhydride or isoxadifen-ethyl was evaluated. These safeners reduced CBG injury from topramezone only. Topramezone was then applied in combination with naphthalic anhydride, isoxadifen-ethyl, cloquintocet-mexyl (cloquintocet), fenchlorazole-ethyl, mefenpyr-diethyl, and benoxacor. These experiments determined that CBG injury was lowest from topramezone in combination with cloquintocet. Additional experiments evaluated topramezone (37 g ha−1) with several rates of cloquintocet and determined that applications at ≥ 28 g ha−1reduced CBG injury similarly. Cloquintocet (28 g ha−1) increased topramezone I50values against CBG, but not large crabgrass or goosegrass. The cytochrome P450 (cP450) inhibitor malathion (1000 g ha−1) reduced topramezone I50values against CBG in one experimental run. Topramezone–cloquintocet combinations warrant further research in field settings.

The reaction of (Z)-2-amino-N′-arylbenzimidamides with 1,8-naphthalic anhydride in ethyl alcohol under reflux conditions gave benzo[4,5] isoquinolino[2,1-a]quinazoline derivatives in good yield.

The liquid-phase oxidative carbonylation of aromatics leading to aromatic carboxylic acids is studied to develop new approaches to 2,6-naphthalenedicarboxylic acid (NDA) preparation. It is shown that the catalytic system Pd(OAc) 2 /K 2 S 2 O 8 allows the synthesis of naphthalic anhydride (NAn) by direct oxidative carbonylation of naphthalene under mild conditions (25 °С, 2 atm СО). The subsequent alkaline hydrolysis of NAn and isomerization of the obtained 1,8-naphthalenedicarboxylic acid salt is known to lead to NDA.

The reaction of (Z)-2-amino-N′-arylbenzimidamides with 1,8-naphthalic anhydride in ethyl alcohol under reflux conditions gave benzo[4,5] isoquinolino[2,1-a]quinazoline derivatives in good yield.

A kind of 1,8-naphthalimide derivative grafted onto Chitosan was synthesized with Chitosan, 4-bromo-N-(2-aminoethyl)-1,8-naphthalimide and 4-bromo-1,8- naphthalic anhydride via substitution and amidation. The structures of compounds was characterized by FT-IR．Thermal stability and fluorescence spectra of the target product were investigated. Compared with 4-bromo-N-(2-aminoethyl)-1,8-naphthalimide, the maximum fluorescent intensity of the 1,8-naphthalimide derivative grafted onto Chitosan was increased 1.25 folds.

The quaternisation of tertiary amines (triethylamine, pyridine and 1, 4-diaza-[2, 2, 2] bicyclooctane) by cyclic anhydrides (phthalic, 4-nitro, 3-nitro-, 3, 5-dinitro, 3, 6-dichloro-and tetrachlorophthalic, naphthalic anhydride) is studied in aprotic media. It appears that the reaction is strongly dependent on substituent and solvent effects. In every case a charge-transfer complex is formed between the two reactants. This complex is a real intermediate on the reaction path. The activation parameters favour the resulting complex mechanism.

New sulfonated and non-sulfonated monomers — dinitro and diamino compounds — were prepared on the basis of 1,3,5-trinitrobenzene (TNB) which is the demethylation product of 2,4,6-trinitrotoluene (TNT). The sulfonated dinitrocompounds interacted with different binuclear bis-phenols under the conditions of aromatic nucleophilic nitrodisplacement reactions. Polyethers of moderate molecular weights were prepared on the basis of dinitrocompound containing electron-withdrawing 3,5-dinitrodiphenyl sulfone-4′-sulfonic acid “bridging” groups. Copolymers and blends with other sulfonated polymers were prepared to improve the film-forming properties of the polyethers developed on the basis of 3,5-dinitrodiphenyl sulfone-4′-sulfonic acid. High molecular weight sulfonated polynaphthylimides were prepared by the interaction of sulfonated diamine containing electron-donating ether group — 3,5-diaminodiphenyl ether-4′-sulfonic acid — with bis(naphthalic anhydride)s. The sulfonated polyethers and polynaphthylimides thus obtained contain sulfonic acid groups in the side chains.

Efficient synthesis of fluorescent probes based on 1,8-naphthalic anhydride from acenaphthene with the help of microwave irradiation is described. Application of microwave dielectric heating helped improve the yield of the products (>85%) and also reduced the formation of undesired side-products.

The chemistry of formation of products of acenaphthene oxidation in the presence of the catalyst containing both manganese and cobalt bromides under batch conditions is discussed. The main reaction products are acenaphthene quinone, acenaphthenol-9, trans-acenaphthylene glycol, naphthalide, and naphthalic anhydride. The sequence of reactions leading to the final products is established. It is shown that the main oxidation product in the presence of the manganese-based catalyst is naphthalic anhydride, and the main product in the presence of the cobalt-based catalyst is acenaphthene quinone. The process and engineering techniques providing for the high overall and fractional yields of the desired products are discussed.

The liquid-phase oxidative carbonylation of aromatics leading to aromatic carboxylic acids is studied to develop new approaches to 2,6-naphthalenedicarboxylic acid (NDA) preparation. It is shown that the catalytic system Pd(OAc) 2 /K 2 S 2 O 8 allows the synthesis of naphthalic anhydride (NAn) by direct oxidative carbonylation of naphthalene under mild conditions (25 °С, 2 atm СО). The subsequent alkaline hydrolysis of NAn and isomerization of the obtained 1,8-naphthalenedicarboxylic acid salt is known to lead to NDA.

A new water-soluble saccharide receptor based on a naphthalic anhydride fluorophore was synthesized from 3-aminophenylboronic acid. The large change in fluorescence intensity (IIo=ca. 0.25) and measured pKa (7.7) make this compound a useful chemosensor at neutral pH.

In the presence of a strong Lewis base, such as Et3N, trithio-1,8-naphthalic anhydride (3) is easily oxidized. Two improved syntheses of trithio-1,8-naphthalic anhydride (3) are described. Trithio-1,8-naphthalic anhydride (3) undergoes Diels-Alder reactions with electron-deficient alkenes to give novel fused heterocyclic compounds (6–11) that then can undergo a novel, gradual desulfuration dimerization with triethyl phosphite to afford 12 and its analogs 13 and 14. The structures of 6–14 are confirmed by microanalysis, IR, and NMR spectroscopy, and MS. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 141–146, 1999

Difficulties with stand establishment are a major factor limiting further agronomic use of native warm season grasses. One significant cause of stand failure is competition with rapidly growing annual weed species during the early development of the perennial native grass. Broad spectrum preemergent herbicides can provide the needed weed control, but only if tolerance exists in the desired grass. Herbicide safeners, synthetic compounds that protect crops from herbicide injury, applied as seed treatments offer a potential strategy to achieving the needed herbicide tolerance where it does not naturally occur. This study tested the efficacy of five herbicide safeners (benoxacor, fenclorim, fluxofenin, naphthalic anhydride, and oxabetrinil) in protecting three native warm season grass species (big bluestem, Andropogon gerardii Vitman; little bluestem, Schizachyrium scoparium (Michx.) Nash; indiangrass, Sorghastrum nutans (L.) Nash) from herbicidal injury caused by preemergent application of S-metolachlor and quantifies this establishment method's impact on early stand performance.

1,4,5,8-Naphthalenetetracarboxylic acid cyclic 1,8-anhydride crystallized from dimethyl sulfoxide (DMSO) as the solvate, C14H6O7.2C2H6OS, in the centrosymmetric space group P1. Two O-H...O hydrogen bonds with O...O distances of 2.592 (3) and 2.598 (3) A are formed, with the two carboxylic acid OH groups as donors and the O atoms of the two inequivalent DMSO molecules as acceptors. The carboxylic H atoms are ordered, as are the carboxylic O atoms. In addition to the conventional hydrogen bonds, there are numerous C-H...O interactions consistent with the large number of potential CH donors and O-atom acceptors. 1,4,5,8-Naphthalenetetracarboxylic 1,8:4,5-dianhydride, C14H4O6, crystallized in the centrosymmetric space group P2(1)/c with half the molecule as the asymmetric unit. Each molecule is involved in four significant C-H...O interactions as a donor and in an additional four as an acceptor. These eight interactions link each molecule to six neighboring molecules, forming a three-dimensional network. Geometric parameters of both substances are in general agreement with analogous parameters for naphthalic anhydride, monosodium 1,4,5,8-naphthalenetetracarboxylic acid cyclic 1,8-anhydride monohydrate and 1,4,5,8-naphthalenetetracarboxylic 1,8:4,5-dianhydride, as reported previously.

Derivatives of 1,8-naphthalic anhydride have been synthesized and their spectroscopic and photochemical properties studied. Whilst these compounds have a good photostability, only derivatives with a primary or secondary amino group, had a good fluorescence quantum yield.

The vibrational spectrum of naphthalic anhydride (NA) is discussed. The material was studied in thin solid films and in KBr and CsI pellets. Fundamental vibrational frequencies were observed using FT-Raman and FTIR transmission and reflection-absorption techniques. The harmonic vibrational frequencies of NA were calculated using Gaussian-92 at RHF/6-31G(d) level of theory. Calculated frequencies, infrared and Raman intensities were used in the vibrational assignment of observed fundamentals. Molecular organization in films evaporated onto a smooth silver metal film is discussed in terms of surface selection rules for reflection-absorption infrared spectroscopy (RAIRS) measurements.

Reaction of naphthalic anhydride (naphthalene-1,8-dicarboxylic anhydride) (1) or of 1,8-bis(hydroxymethyl)naphthalene (3) with LiAlH4 in refluxing THF yields the benzonorcaradiene derivatives 2 in yields of up to 50%. It is proposed that in the formation of this (strained) product an anti-hydroalumination reaction is involved, which is facilitated by the assistance of a neighbouring alkoxide function.

The efficacy of the safeners naphthalic anhydride (NA), R-29148, benoxacor, and dichlormid as protectants of corn against injury from the methyl ester of tribenuron was evaluated under greenhouse conditions. Tribenuron applied alone reduced the root length of both 'Pioneer 3180' and 'Northrup-King 9283' corn. The concentration of tribenuron causing 50% reduction of corn root length (GR50) was 1 ,uM. NA applied as a seed dressing at 0.5 and 1.0% (w/w) was the most effective of the four safeners tested and provided excel- lent protection to both corn hybrids against 1, 2, and 4 jM tribenuron. Soaking corn seeds in an aqueous solution of R-29148 containing 0.5, 1, or 2 mM protected 'Pioneer 3180' against 1 ,uM of tribenuron. The safening efficacy of R-29148 against tribenuron injury to 'Northrup-King 9283' corn was limited. Dichlormid and benoxacor, were less effective as tribenuron safeners and offered partial protection to both corn hybrids. Individual applications of the synergist piperonyl butoxide (PBO) at 0.1 and 0.2 mM did not affect the growth of corn seedlings. PBO synergized the activity of all concentrations of tribenuron, but only on the 'Northrup- King 9283' hybrid. These results demonstrate that the toler- ance of corn to tribenuron can be enhanced with the use of safeners such as NA and R-29148, and that oxidative reac- tions may be involved in the metabolism of tribenuron by corn. Nomenclature: Benoxacor, (4-dichloroacetyl)-3,1-dihy- dro-3-methyl-2H-1,4-benzoxazine; dichlormid, 2,2-di- chloro-N,N-di-2-propenylacetamide; NA, 1,8-naphthalic anhydride; piperonyl butoxide, a(2-(2-butoxyethoxy)- ethoxyl-4,5-methylenedioxy-2-propyltoluene; R-29148, 3- (dichloroacetyl)-2,2,5-trimethyl-1,3-oxazolidine; tri- benuron, 2-(((((1-methoxy-6-methyl-1,3,5-triazin-2- yl)methylamino)carbonyl)aminoJsulfonyl)benzoic acid; corn, Zea mays L. 'Pioneer 3180' and 'Northrup-King 9283.' Additional index words. Antagonism, antidotes, synergism, synergist.