A Rare Case Report of Intra-abdominal Mucormycosis Complicating Acute Pancreatitis.

Intra-abdominal infections are known to complicate the course of acute pancreatitis. Invasive fungal infections (Candida spp.) are not the uncommon microorganisms which isolate from intra-abdominal specimen in acute necrotizing pancreatitis. However, we are reporting first case of invasive gastric mucormycosis in a postpartum acute pancreatitis patient. How to cite this article: Bhaskar BK, Gutte SH, Gurjar M, Saran S, Rahul R, Sengar P. A Rare Case Report of Intra-abdominal Mucormycosis Complicating Acute Pancreatitis. Indian J Crit Care Med 2022;26(6):736-738.

First Study on Phosphonite-Coordinated Ruthenium Sensitizers for Efficient Photocatalytic Hydrogen Evolution.

For the first time we report the design and syntheses of phosphonite coordinated ruthenium(II) sensitizers bearing CN̂N ligand and/or terpyridine derivatives carboxylate anchor (GS11, GS12. and GS13) and its application for hydrogen production over Pt-TiO2 system. These heteroleptic complexes exhibit broad metal-to-ligand charge transfer transition band over the whole visible regime extending up to 900 nm. DFT calculations of these complexes show that the HOMO is distributed over the Ru and Cl atom whereas; LUMO is localized on the polypyridile ligand, which are anchored on TiO2 surface. Among the sensitizers tested for photocatalytic hydrogen evolution, GS12 exhibited a maximum turnover number (TON) 8605 (for 8 h), which is very high compared to the reference sensitizer (N719) with TON 163 under similar evaluation condition. The dependence of the hydrogen evolution rate at different pH using GS11, GS12, GS13, and DX-1-sensitized Pt-TiO2 has been studied and the maximum H2 production yield was obtained at pH 7 for all sensitizers.

Dithiafulvalene functionalized diketopyrrolopyrrole based sensitizers for efficient hydrogen production.

We have designed and synthesized two new diketopyrrolopyrrole (DPP) based organic sensitizers (DPPCA and DPPCN) with the dithiafulvalene (DTF) unit as donor and cyanoacrylic acid/malononitrile as acceptor moieties. These dyes showed excellent efficiency of photocatalytic hydrogen production over a Pt-TiO2 composite via solar-induced water splitting. The sensitizers showed broad absorptions over the wide visible regime (500-800 nm). In DPPCN, the malononitrile moiety led to strong intra-molecular charge transfer, as evidenced by red shifted (∼24 nm) absorption maxima with highly enhanced molar absorptivity (108 190 M(-1) cm(-1)). The electrochemical characterization of as-prepared sensitizers confirmed the feasible electron injection from the dye to the TiO2 conduction band (CB) which has been further validated by theoretical studies. In this study, the rate of the photocatalytic activity was found to be dependent on the acceptor part of the dye molecule as DPPCN sensitized Pt-TiO2 (DNPT) exhibited remarkable (1208 µmol) hydrogen evolution yield in comparison to DPPCA sensitized Pt-TiO2 (DAPT) (840 µmol). The rigid DPP core made the sensitizers significantly photo-stable as affirmed by their high hydrogen production efficiency over 80 h of prolonged irradiation. As predicted from density functional theory (DFT) calculations, ground state geometry of the dyes was almost planar, facilitating continuous conjugation throughout the molecule. Time-dependent DFT (TD-DFT) calculations were also carried out to make clear the understanding of charge transfer transition of the dye molecules.

Design and synthesis of novel anthracene derivatives as n-type emitters for electroluminescent devices: a combined experimental and DFT study.

Six novel anthracene-oxadiazole derivatives, 4a (2-(4-(anthracen-9-yl)phenyl)-5-p-tolyl-1,3,4-oxadiazole), 4b (2-(4-(anthracen-9-yl)phenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole), 4c (2-(4-(anthracen-9-yl)phenyl)-5-(4-methoxyphenyl)-1,3,4-oxadiazole), 8a (2-(4-(anthracen-9-yl)phenyl)-5-m-tolyl-1,3,4-oxadiazole), 8b (2-(3-(anthracen-9-yl)phenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole) and 8c (2-(3-(anthracen-9-yl)phenyl)-5-(3,4,5-trimethoxyphenyl)-1,3,4-oxadiazole) have been synthesized and characterized for use as emitters in organic light emitting devices (OLEDs). They show good thermal stability (T(d), 297-364 °C) and glass transition temperatures (T(g)) in the range of 82-98 °C, as seen from the thermo gravimetric analysis and differential scanning calorimetric studies. The solvatochromism phenomenon and electrochemical properties have been studied in detail using UV-Vis absorption, fluorescence spectroscopy and cyclic voltammetry. TD-DFT calculations have been carried out to understand the electrochemical and photophysical properties. The spatial structures of 4b and 8c are further confirmed by X-ray diffraction analysis. Un-optimized non-doped electroluminescent devices were fabricated using these anthracene derivatives as emitters with the following device configuration: ITO (120 nm)/α-NPD (30 nm)/4a-4c or 8a-8c(35 nm)/BCP (6 nm)/Alq3 (28 nm)/LiF (1 nm)/Al (150 nm). Among all the six compounds, 8a displays the maximum brightness of 1728 cd m(-2) and current efficiency 0.89 cd A(-1). Furthermore, as an electron transporter, 8a exhibited superior performance (current efficiency is 11.7 cd A(-1)) than the device using standard Alq3 (current efficiency is 8.69 cd A(-1)), demonstrating its high potential for employment in OLEDs. These results indicate that the new anthracene-oxadiazole derivatives could play an important role in the development of OLEDs.

Application of solution processable squaraine dyes as electron donors for organic bulk-heterojunction solar cells.

New low bandgap small molecules based on a squaraine (SQ) chromophore, bis[4-(2,6-di-tert-butyl)vinylpyrylium]squaraine (TBU-SQ), bis[2,6-di-tert-butyl-4-(prop-1-en-2-yl)pyrylium]squaraine (MeTBU-SQ) and bis[4-(but-1-en-2-yl)-2,6-di-tert-butylpyrylium]squaraine (EtTBU-SQ), were synthesized and used as electron donors along with PC70BM for their application in solution processed organic bulk-heterojunction (OBHJ) solar cell (SC). The long wavelength of these SQ dyes are located in between 650-750 nm in thin films and the optical bandgaps are about 1.64, 1.52 and 1.48 eV, respectively. The electrochemical properties of these SQ dyes indicate that they are well suited for the fabrication of OBHJSCs as electron donors along with fullerene derivatives as electron acceptors. The OBHJ photovoltaic (PV) devices fabricated with the blend of TBU-SQ:PC70BM, MeTBU-SQ:PC70BM and EtTBU-SQ:PC70BM cast from chloroform (CF) solvent exhibited a power conversion efficiency (PCE) of 1.71%, 2.15%, and 1.89%, respectively. The PCE of the OBHJSCs based on MeTBU-SQ:PC70BM blends cast from DIO-THF (DIO = 1,8-diiodooctane) additive solvent and cast from DIO-THF with subsequent thermal annealing have been further improved up to 2.73% and 3.14%, respectively. This enhancement in the PCE is attributed to the improvement in the crystalline nature of the blend and more balanced charge transport resulting from the higher hole mobility. All these results have been supported by the quantum chemical calculations.

Unusual regioselective electrophilic substitutions in quinoline foldamers: conceptual DFT and frontier molecular orbital analysis reveal the crucial role of folding and substituents.

We carried out a detailed computational investigation of an earlier experimentally observed, unusual, regioselective, electrophilic halogenation in helically folded quinoline oligoamides. In the experimental studies, halogenation occurred selectively at a given monomer of a foldamer substituted with electron-withdrawing groups at the N terminus, although apparently identical reactive sites were available to react with the incoming electrophile. On the other hand, the selectivity was lost with weakly electron-donating groups. To gain an insight into the regioselective preference of bromination in quinoline foldamers, conceptual DFT was used to calculate the local nucleophilicity index of various foldamers of different sizes and with different substituents, and it was found that the predicted reaction centers were in line with the experimental results. Frontier molecular orbital analysis was used to understand this behavior. A detailed study of the hypothetical linear conformation of the tetramer for comparison with the folded conformation was carried out. In the case of a linear conformer, the HOMO is localized on specific monomers irrespective of substitution, but upon folding delocalization is observed, which is larger for the weakly electron-donating groups when compared with the electron-withdrawing groups. In the case of strongly donating groups there is no delocalization, even upon folding. The behavior remains the same when the size of the helix is increased (octamer). Thus, it is clearly seen in this work that the combined effects of conformations and substituents dictate the regioselectivity in the folded oligoamides; this knowledge will have a profound effect on the field of foldamer chemistry.

The ESI CAD fragmentations of protonated 2,4,6-tris(benzylamino)- and tris(benzyloxy)-1,3,5-triazines involve benzyl-benzyl interactions: a DFT study.

The electrospray ionization collisionally activated dissociation (CAD) mass spectra of protonated 2,4,6-tris(benzylamino)-1,3,5-triazine (1) and 2,4,6-tris(benzyloxy)-1,3,5-triazine (6) show abundant product ion of m/z 181 (C(14) H(13)(+)). The likely structure for C(14) H(13)(+) is α-[2-methylphenyl]benzyl cation, indicating that one of the benzyl groups must migrate to another prior to dissociation of the protonated molecule. The collision energy is high for the 'N' analog (1) but low for the 'O' analog (6) indicating that the fragmentation processes of 1 requires high energy. The other major fragmentations are [M + H-toluene](+) and [M + H-benzene](+) for compounds 1 and 6, respectively. The protonated 2,4,6-tris(4-methylbenzylamino)-1,3,5-triazine (4) exhibits competitive eliminations of p-xylene and 3,6-dimethylenecyclohexa-1,4-diene. Moreover, protonated 2,4,6-tris(1-phenylethylamino)-1,3,5-triazine (5) dissociates via three successive losses of styrene. Density functional theory (DFT) calculations indicate that an ion/neutral complex (INC) between benzyl cation and the rest of the molecule is unstable, but the protonated molecules of 1 and 6 rearrange to an intermediate by the migration of a benzyl group to the ring 'N'. Subsequent shift of a second benzyl group generates an INC for the protonated molecule of 1 and its product ions can be explained from this intermediate. The shift of a second benzyl group to the ring carbon of the first benzyl group followed by an H-shift from ring carbon to 'O' generates the key intermediate for the formation of the ion of m/z 181 from the protonated molecule of 6. The proposed mechanisms are supported by high resolution mass spectrometry data, deuterium-labeling and CAD experiments combined with DFT calculations.

Functionalized styryl bipyridine as a superior chelate for a ruthenium sensitizer in dye sensitized solar cells.

The new sensitizer MC119 has been synthesized and the solar cell constructed with 0.25 cm(2) active area photoelectrode in combination with an electrolyte composed of 0.6 M dimethylpropyl-imidazolium iodide (DMPII), 0.05 M I(2), 0.5 M TBP and 0.1 M LiI in acetonitrile achieved a solar to electric energy conversion efficiency (η) of 8.36% under Air Mass (AM) 1.5 sunlight, while the reference N719 sensitized solar cell exhibited η-value of 7.2%.

Enhanced diradical nature in oxyallyl derivatives leads to near infra red absorption: a comparative study of the squaraine and croconate dyes using computational techniques.

We apply many criteria to estimate the diradical character of the ground state singlets of several oxyallyl derivatives. This is carried out as the oxyallyl derivatives like squaraine and croconate dyes can be represented by both mesoionic and diradical formulas, the domination of which would characterize its lowest energy transition. One criterion applied is the singlet-triplet gap, which is known to be inversely proportional to the diradical character. Another criterion is the occupation number; this is determined for the symmetry broken state of the molecules in the unrestricted formalism, and the difference of occupation in the HOMO and LUMO is related to the diradical character. The diradical character of all of the croconates and few squaraines is estimated to be large. All of these have absorption above 750 nm and can be classified as near infrared (NIR) dyes, leading to the inference that NIR absorptions in these molecules are largely due to the dominance of the diradical character. To understand the reliability of the DFT methods for the absorption property predictions of these molecules, TD-DFT studies to calculate the vertical excitation energies have been carried out, using the B3LYP/ BLYP exchange correlation functionals and the LB94 asymptotic functional with and without the inclusion of solvent. The deviations, in both the squaraine series (average lower diradical character), are found to be systematic, and with the inclusion of the solvent in the calculation, the deviations decrease. The best least-squares fit with the experimentally observed values using B3LYP /6-311G(d, p) for the symmetric squaraines yields an R value of 0.92 and, for the unsymmetric squaraines, an R value of 0.936. With inclusion of the solvent, the R value is 0.96 for the symmetric squaraines and 0.961 for the unsymmetric squaraines, indicating that these DFT functionals with linear scaling may be used to study these systems. The croconate dyes, however, have larger deviation from the experimentally observed values in all of the functionals studied even after inclusion of the solvent effects. The deviations are also not systematic. The deviation with respect to the experiment in this case is attributed to the average larger diradical character in this series.

Age-related changes in bone turnover markers and ovarian hormones in premenopausal and postmenopausal Indian women.

This study characterizes age-related changes in bone turnover markers in relation to ovarian hormones. The data (N = 236) were divided into 5-year age bands and three groups: premenopausal (Group I, N = 139), perimenopausal (Group II, N = 30), and postmenopausal (Group III, N = 67). Age-related increases in mean parathyroid hormone (PTH), osteocalcin (OC), and collagen telopeptide (CTx) levels were observed. Women in Group II (N = 37) with osteopenia had lower levels of E1G (P<0.001) with normal FSH levels as compared to 50 women in the same group with normal bone mineral density (BMD). Their mean OC levels were reduced (P<0.05) and CTx levels were significantly elevated (P<0.01). The mean E1G levels were significantly lower (P<0.001) and mean CTx levels were significantly higher (P<0.001) in 30 perimenopausal women (Group II) compared to premenopausal women. In 28 postmenopausal women (group III) the mean BMD levels and E1G were significantly lower (P<0.001) with elevated FSH levels (P<0.001). Increased CTx levels (P<0.0001) reflected a higher rate of bone resorption. These observations suggest that perimenopausal women with low E1G, elevated FSH should be screened for osteoporosis, and it may be valid to combine simultaneous measurements of bone turnover markers with ovarian hormones when screening women at risk for osteoporosis.

Origin of near-infrared absorption and large second hyperpolarizability in oxyallyl diradicaloids: a three-state model approach.

Bis(benzofuranonyl)methanolate (BM4i4i) dye and croconate dyes (derivatives of oxyallyl molecules) in general are known to have intense transitions in the near-infrared (NIR) region, indicating small transition energies and large transition dipole moments. These molecules have been reported in the literature to have very large resonant third-order nonlinear optical (NLO) susceptibilities and molecular hyperpolarizabilities (gamma). In this work we investigate using density functional theory (DFT)/ab initio/symmetry adapted cluster-configuration interaction (SAC-CI) techniques the oxyallyl substructure and attribute the NIR transition and the NLO activity to this substructure, which is common in all these molecules. Using valence bond (VB) theory, an analysis of a three-state model of this substructure is carried out. It is seen that the mixture of an intermediate diradical character and some zwitterionic character in the molecule and a large coupling between these two VB resonance forms is responsible for large gamma values. This can be used as a design principle for increasing NLO activity in oxyallyl derivatives.

Structure, bonding, and lowest energy transitions in unsymmetrical squaraines: a computational study.

Natural resonance theory (NRT) and natural bond orbital (NBO) analysis have been carried out on a simple symmetrical and an unsymmetrical substituted squaraine with a view of understanding the structure of the latter type of squaraines. It is found that there are some fundamental differences in the structure and bonding between these two types of squaraines particularly in the resonance weights and delocalization energies. These differences are expected to reflect in the low energy transitions and charge transfer in these squaraines. To investigate this, the nature of the lowest energy transitions occurring on excitation in unsymmetrical squaraines has been studied using high-level symmetry adapted cluster-configuration interaction method (SAC/SAC-CI) and compared with reported experimental observations. In general the agreement with the experimental data is very good. The transition dipole moment always lies on the pi-backbone and is quite large in magnitude. The ground state dipole moment in some cases does not change in the excited state upon excitation while in some other cases there is a large reduction/enhancement in the magnitude indicative of some charge rearrangement in this direction. Inclusion of the solvent using the IEFPCM model, a slightly better agreement with the experiment is found in some cases. Studies are carried out with a different basis set and it is found that the change in basis set has very little effect on the transition energies. In the case of weak side donor groups attached to the central ring the larger charge transfer to the central acceptor ring in general takes place from the O- atoms of the squarylium moiety while in the case of strong donors the charge transfer from the O- atoms to the central rings drop down. We have not observed any correlation between the charge transfer in the excited state to the central ring from the side donor groups and the lowest energy excitation in the molecules. Reduction of the HOMO-LUMO gap (an indication of increase of the diradicaloid character) always leads to a bathochromic shift.

Electronic structures and absorption spectra of linkage isomers of trithiocyanato (4,4',4' '-tricarboxy-2,2':6,2' '-terpyridine) ruthenium(II) complexes: a DFT study.

Black dye (BD), isomer 1 ([Ru(II)(H3-tctpy)(NCS)3](-1), where H3-tctpy = 4,4',4' '-tricarboxy-2,2':6,2' '-terpyridine) is known to be an excellent sensitizer for dye-sensitized solar cells and exhibits a very good near-IR photo response, compared to other ruthenium dyes. Because isothiocyanate is a linear ambidentate ligand, BD has three other linkage isomers, [Ru(H3-tctpy)(NCS)2(SCN)](-1), isomer 2 and 2', and [Ru(H3-tctpy))(SCN)3](-1), isomer 3. In this study, we have calculated the geometry of BD and its isomers by DFT. Further, we have analyzed the bonding in these isomers using NBO methods. TDDFT calculations combined with scalar relativistic zero-order regular approximations (SR-ZORA) have been carried out to simulate the absorption spectra. Calculations have been performed for the isomers both in vacuo and in solvent (ethanol). The inclusion of the solvent is found to be important to obtain spectra in good agreement with the experiment. The first absorption bands are dominated by the metal-to-ligand charge transfer (MLCT) and ligand-to-ligand charge transfer (LLCT).

Synthesis and antibacterial activity of various substituted s-triazines.

Series of substituted-s-triazines (1-22) were synthesized and evaluated for their in vitro antibacterial activity against six representative Gram-positive and Gram-negative bacterial strains. Many compounds have displayed comparable antibacterial activity against Bacillus sphaericus and significantly active against other tested organisms with reference to streptomycin.

Electronic properties of anthracene derivatives for blue light emitting electroluminescent layers in organic light emitting diodes: a density functional theory study.

Molecular level parameters are investigated computationally to understand the factors that are responsible for the higher efficiency in derivatives of 9,10-bis(1-naphthyl)anthracene (alpha-ADN), 9,10-bis(2-naphthyl)anthracene (beta-ADN), their tetramethyl derivatives (alpha,beta-TMADN) and the t-Bu derivative (beta-TBADN) as blue light emitting electroluminescent (EL) layers in organic light emitting diodes (OLEDs). DFT studies at the B3LYP/6-31G(d,p) level have been carried out on the substituted anthracenes. The absorption spectra are simulated using time dependent DFT methods (TD-DFT) whereas the emission spectra are approximated by optimizing the excited state by HF/CI-Singles and then carrying out the vertical CI calculations by the TD-DFT method. The reorganization energy for estimating the hole and electron transport is calculated. The transfer integrals between parallely stacked molecules in the bulk state are estimated by calculating the electronic splitting. The substituted anthracenes are compared with unsubstituted anthracene and yet untested 9,10-dianthrylanthracene (TANTH). A larger and slower buildup of the electrons and holes in the EL layer, due to the higher reorganization energy and smaller electronic coupling between the adjacent molecules could lead to an increase in hole-electron recombination in the layer and thus increase the efficiency.

Synthesis and antibacterial activity of 2,4,6-tri substituted s-triazines.

Various 2,4,6-tri substituted s-triazines were synthesized and screened for antibacterial activity against Gram-positive and Gram-negative organisms. These s-triazine derivatives displayed high in vitro antibacterial activities comparable to penicillin and streptomycin against tested microorganisms.

Role of the oxyallyl substructure in the near infrared (NIR) absorption in symmetrical dye derivatives: A computational study.

It is well-known from experimental studies that the oxyallyl-substructure-based squarylium and croconium dyes absorb in the NIR region of the spectrum. Recently, another dye has been reported (J. Am. Chem. Soc. 2003, 125, 348) which contains the same basic chromophore, but the absorption is red-shifted by at least 300 nm compared to the former dyes and is observed near 1100 nm. To analyze the reasons behind the large red shift, in this work we have carried out symmetry-adapted cluster-configuration interaction (SAC-CI) studies on some of these NIR dyes which contain the oxyallyl substructure. From this study, contrary to the earlier reports, it is seen that the donor groups do not seem to play a major role in the red-shift of the absorption. On the other hand, on the basis of the results of the high-level calculations carried out here and using qualitative molecular orbital theory, it is observed that the orbital interactions play a key role in the red shift. Finally, design principles for the oxyallyl-substructure-based NIR dyes are suggested.

Near-infrared absorption in symmetric squarylium and croconate dyes: a comparative study using symmetry-adapted cluster-configuration interaction methods.

Symmetric croconate (CR) and squarylium dyes (SQ) are well-known near-infrared (NIR) dyes and, in general, are considered to be donor-acceptor-donor type molecules. It is established in the literature that CR dyes absorb in a longer wavelength region than the corresponding SQ dyes. This has been attributed to the CR ring being a better acceptor than the SQ ring. Thus increasing the donor capacity should lead to a bathochromic shift in both SQ and CR. On the other hand, some experiments reported in the literature have revealed that increasing the conjugation in the donor part of the SQ molecule leads first to red shift, which upon a further increase of the conjugation changes to a blue shift. Hence, to understand the role of the central ring and the substitutions in the absorption of these dyes, we carried out high-level symmetry-adapted cluster-configuration interaction (SAC-CI) calculations of some substituted SQ and CR dyes and compare the absorption energy with the existing experimental data. We found that there is very good agreement. We also carried out SAC-CI calculations of some smaller model molecules, which contain the main oxyallyl substructure. We varied the geometry (angle) of the oxyallyl subgroup and the substitution in these model molecules to establish a correlation with the bathochromic shift. We found that the charge transfer is very small and does not play the key role in the red shift, but on the other hand, the perturbation of the HOMO-LUMO gap (HLG) from both the geometry and substitution seems to be responsible for this shift. We suggest as a design principle that increasing the donor capacity of the groups may not help in the red shift, but introducing groups which perturb the HLG and decrease it without changing the MO character should lead to a larger bathochromic shift.

Generation and characterization of ionic and neutral P(OH)2+/* in the gas phase by tandem mass spectrometry and computational chemistry.

The bicoordinated dihydroxyphosphenium ion P(OH)2+ (1+) was generated specifically by charge-exchange dissociative ionization of triethylphosphite and its connectivity was confirmed by collision induced dissociation and neutralization-reionization mass spectra. The major dissociation of 1+ forming PO+ ions at m/z 47 involved another isomer, O=P-OH2+ (2+), for which the optimized geometry showed a long P-OH2 bond. Dissociative 70-eV electron ionization of diethyl phosphite produced mostly 1+ together with a less stable isomer, HP(O)OH+ (3+). Ion 2+ is possibly co-formed with 1+ upon dissociative 70-eV electron ionization of methylphosphonic acid. Neutralization-reionization of 1+ confirmed that P(OH)2* (1) was a stable species. Dissociations of neutral 1, as identified by variable-time measurements, involved rate-determining isomerization to 2 followed by fast loss of water. A competitive loss of H occurs from long-lived excited states of 1 produced by vertical electron transfer. The A and B states undergo rate-determining internal conversion to vibrationally highly excited ground state that loses an H atom via two competing mechanisms. The first of these is the direct cleavage of one of the O-H bonds in 1. The other is an isomerization to 3 followed by cleavage of the P-H bond to form O=P-OH as a stable product. The relative, dissociation, and transition state energies for the ions and neutrals were studied by ab initio and density functional theory calculations up to the QCISD(T)/6-311+G(3df,2p) and CCSD(T)/aug-cc-pVTZ levels of theory. RRKM calculations were performed to investigate unimolecular dissociation kinetics of 1. Excited state geometries and energies were investigated by a combination of configuration interaction singles and time-dependent density functional theory calculations.