Syntheses and crystal structures of oxovanadium(V) complexes derived from N′-[1-(2-hydroxynaphthyl)ethylidene]-4-nitrobenzohydrazide and 2-hydroxy-N′-[1-(2-hydroxynaphthyl)ethylidene]benzohydrazide

Reactions of bis(acetylacetonato)oxovanadium(IV) with N??-[1-(2-hydroxynaphthyl)ethylidene]-4-nitrobenzohydrazide (H₂HNB) and 2-hydroxy-N??-[1-(2-hydroxynaphthyl)ethylidene]benzohydrazide (H₂HHB), respectively, product two oxovanadium(V) species with the formulas [VO(OMe)(HNB)]₂ (I) and [VO(OMe)(HHB)] (II). The complexes I and II have been characterized by elemental analysis, IR spectra, and single crystal X-ray diffraction. The crystal of I is monoclinic: space group P2₁/n, a = 8.208(2), b = 14.528(3), c = 16.418(3) ?, ?? = 97.887(3)°, V = 1939.3(7) ?³, Z = 2. The crystal of II is triclinic: space group P $P\bar 1$ a = 8.334(2), b = 10.236(2), c = 11.337(2) ?, ?? = 80.91(3)°, ?? = 75.41(3)°, ?? = 75.63(3)°, V = 902.0(3) ?³, Z = 2. Complex I is a methoxide-bridged dimeric oxovanadium(V) complex, and complex II is a mononuclear oxovanadium(V) complex. The V atom in I is in an octahedral coordination, and that in II is in a square pyramidal coordination.     

Synthesis and crystal structure of copper and zinc chloride complexes with bidentate imidazole-benzimidazole ligands

In order to elucidate substituent effects in the 2-(1-vinyl- and 2-(1-ethyl)imidazol-2-yl)benzimidazole molecules (L and L??) and the effect of complexing metals on the conformation, the degree of bond conjugation, and molecular interactions in the crystals, two complexes, [Cu(L)Cl₂] (I) and [Zn(L??)Cl₂] (II), were studied by X-ray diffraction. The crystals are monoclinic, I: a = 6.270(1) ?, b = 13.316(1) ?, c = 16.069(1) ?, ?? = 102.36(1)°, space group P2₁/c, R = 0.042; II: a = 10.216(1) ?, b = 10.297(1) ?, c = 13.844(1) ?, ?? = 107.19(1)°, space group P2₁/n, R = 0.029. The structural function of both L in I and L?? in II is N,N-bidentate chelating. At the same CN = 4, the coordination polyhedra of the complexing metals are different, a distorted square of copper in I and a distorted tetrahedron of zinc in II.     

On non-Euclidean crystallography, some football manifolds

In polyhedral crystallography, non-Euclidean possibilities come into considerations as well. The so-called football manifolds appearing in the Bolyai?CLobachevskian hyperbolic space (H ³) can model ??fullerens?? very probably. This may give us the feeling that??in atomic measure??space can wear non-Euclidean structures, e.g., hyperbolic (H ³), spherical (S ³) and other ones, respectively. Such phenomena as pentagonal or decagonal symmetry and the discovery of quasicrystals might strengthen these impressions. We examine here some Archimedean solids: (4, 6, 6) in E ³ (the truncated octahedron in the classical Euclidean space, for analogue as motivation, Fig.?1); (5, 6, 6) the ??real football?? (now in H ³, Fig.?2, from Molnár in Proceedings of International Conference on Differential Geometry and Its Applications, 1988), (3, 10, 10) in H ³ (Fig.?3 from Molnár in the previous Proceedings); an extra solid (4, 6, 8) with two manifolds on it in H ³ (Figs.?4, 5), published first time in this paper. Furthermore (3, 8, 8) will be realized in the spherical space S ³ (Fig.?6). We can study this classical example as a simple non-Euclidean one also for motivation to our method (see also Molnár in Acta Cryst A61:542?C552, 2005, as an introductory paper). Each of them will be a manifold, i.e., it can be endowed with an appropriate face pairing (topological glueing), so that every point has a ball-like neighborhood in the corresponding space, especially of constant curvature, but completely in the classical analogy. In addition, each manifold will be compact (bounded and closed) whose fundamental group can be generated by two screw motions.     

Chinolizine und Indolizine,XIII. Acyl-2-hydroxy-4-chinolizinone

The reaction of 2-picolylketones (1 a, b) with reactive trichlorophenyl malonates (2 a–f) leads to 1-acyl-2-hydroxy-4-quinoliziones (3 a–i) which can be easily deacylated by boiling hydrochloric acid yielding 4-quinolizinones4 a–f. The 3-acetyl-2-hydroxy-4-quinolizinones6 and8 are obtained byKlosa-Ziegler acylation of4 a and7, respectively. The reaction of the acetyl compound3 a with acetic anhydride yields the 2-pyrone derivative9, whereas the propionyl derivative3 g yields the 4-pyrone10 under the same conditions. Nitration of3 e does not give the 1-nitro derivative12 but rather the 1,3-dinitro compound11.     

The reaction of ammonium tetra(isothiocyanato)diamminechromate(III) with ?-caprolactam in aqueous solution. Revised refinement of the structure of (HCpl2)3[Cr(NCS)6]

A reaction of ammonium tetra(isothiocyanato)diamminechromate(III) (ammonium reineckate) with ?-caprolactam in aqueous solution at different pH values gave the novel complexes (NH₄)[Cr(NH₃)₂(NCS)₄] · 7Cpl (I), (NH₄)[Cr(NH₃)₂(NCS)₄] · 2.5Cpl · 0.5(H₂O) (II), and (HCpl₂)[Cr(NH₃)₂(NCS)₄] (III), where Cpl is ?-caprolactam (?-C₆H₁₁NO). The crystals of complexes I?CIII are triclinic, space group $P\bar 1$ ; I: a = 12.7058(4) ?, b = 13.2544(4) ?, c = 19.4487(7) ?, ?? = 105.2360(10)°, ?? = 106.6410(10)°, ?? = 91.5290(10)°, V = 3009.37(17) ?³, ??_calc = 1.245 g/cm³, Z = 2; II: a = 12.3144(5) ?, b = 12.6518(5) ?, c = 23.3300(8) ?, ?? = 75.4580(10)°, ?? = 80.0760(10)°, ?? = 61.0830(10)°, V = 3074.1(2) ?³, ??_calc = 1.358 g/cm³, Z = 4; III: a = 6.4701(4) ?, b = 12.5973(9) ?, c = 16.5556(12) ?, ?? = 108.769(2)°, ?? = 98.543(2)°, ?? = 90.345(2)°, V = 1261.36(15) ?³, ??_calc = 1.437 g/cm³, Z = 2. The structure refinement for (HCpl₂)₃[Cr(NCS)₆] (IV) was revised. Like complex III, complex IV contains the cation (HCpl₂)⁺ stabilized by a strong hydrogen bond between the O atoms of the ?-caprolactam molecules; the cation was structurally characterized for the first time.     

Synthesis, crystal structures, and luminescence spectra of the coordination compounds of cadmium(II) iodide with hexamethylenetetramine

Coordination compounds [Cd_1.5I₃(HMTA) · H₂O] (I) and [CdI₂(HMTA) · H₂O] (II) are synthesized by the reaction of CdI₂ with hexamethylenetetramine (HMTA, C₆H₁₂N₄) with the 1: 1 ratio in ethanol, and their structures are determined. The crystals of compound I are triclinic, space group P $ \bar 1 $ , a = 8.027(1), b = 9.391(1), c = 10.382(1)?, ?? = 66.64(1)°, ?? = 86.18(1)°, ?? = 73.63(1)°, V = 749.2(1) ?³, ??_calcd = 3.136 g/cm³, Z = 2. The crystals of compound II are triclinic, space group P $ \bar 1 $ , a =7.713(1), b = 8.192(1), c = 12.101(1)?, ?? = 80.32(1)°, ?? = 89.57(1)°, ?? = 7.30(1)°, V = 725.0(1) ?³, ??_calcd = 2.402 g/cm³, Z = 2. Structure I includes two types of cadmium complexes. The Cd(1) atom is coordinated through the octahedral mode by three pairs of the I, N(HMTA), and O(H₂O) atoms. The coordination polyhedron of the Cd(2) atom is a distorted tetrahedron (three I atoms and one N atom). The structure contains infinite strips consisting of tetranuclear cyclic fragments joined by the Cd(1) atoms due to the bridging iodine and nitrogen atoms. In structure II, the Cd atom is coordinated through the tetrahedral mode by two iodide ions and the N(HMTA) and O(H₂O) atoms. The interaction between the complexes occurs due to hydrogen bonds O-H??N to form supramolecular chains along the direction [010]. In each HMTA molecule, one of four nitrogen atoms is a proton acceptor in the hydrogen bonds, one nitrogen atom is coordinated, and two N atoms are terminal. Compound II in the solid state has photoluminescence with maxima at 443, 470, and 518 nm.     

π-Complexes of copper(I) halides with 3-(allylamino)-(C3H5NHC2H4CN, Apn) and 3-(diallylamino)-((C3H5)2NC2H4CN, Dapn)-propanenitrile. syntheses and crystal structures of compounds [CuCl(Apn)], [(H+Apn)Cu2Cl3], [(H+Dapn)CuCl2], and [(H+Dapn)CuBr2]

The ??-complexes [CuCl(C₃H₅NHC₂H₄CN)] (I), [(C₃H₅NH₂C₂H₄CN)Cu₂Cl₃] (II), [((C₃H₅)₂NHC₂H₄CN)CuCl₂] (III), and [((C₃H₅)₂NHC₂H₄CN)CuBr₂] (IV) are obtained as single crystals by the ac electrochemical synthesis on copper wire electrodes from ethanolic solutions of 3-(allylamino)propanenitrile, 3-(diallylamino)propanenitrile, and CuX₂ (X = Cl, Br). Their crystal structures are determined. The crystals of compounds I, III, and IV are monoclinic, space group P2₁/c, Z = 4. The crystals of compound II are triclinic, space group P $\bar 1$ , Z = 2. The unit cell parameters are a = 11.125(4), b = 8.769(4), c = 8.570(4) ?, ?? = 90.94(4)°, V = 835.9(6) ?³ (I); a = 6.2566(4), b = 7.5975(6), c = 11.1251(8) ?, ?? = 90.896(6)°, ?? = 92.827(5)°, ?? = 94.340(5)°, V = 526.57(7) ?³ (II); a = 11.656(4), b = 6.992(4), c = 14.681(5) ?, ?? = 100.89(4)°, V = 1174.9(9) ?³ (III); a =11.845(4), b = 7.282(4), c=14.855(5) ?, ?? = 100.37(4)°, V = 1260.4(9) ?³ (IV). The coordination mode of the Cu(I) atom in complex I includes two halogen atoms, the C=C bond, and the secondary amine N atom. The coordination environment in isostructural crystals of complexes III and IV is formed by the C=C bond and three halogen atoms as in complex II.     

Thermal properties of novel polymers based on poly(hydantoin-methyl-p-styrene) and their substrates

The following compounds have been synthesized: (a) hydantoins 5,5-dimethylimidazolidine-2,4-dione (1), 1??,3??-dihydrospiro[imidazolidine-4,2??-indene]-2,5-dione (2), 3??,4??-dihydro-1??H-spiro[imidazolidine-4,2??-naphthalene]-2,5-dione (3); (b) monomers: 5,5-dimethyl-3-(4-vinylbenzyl)imidazolidine-2,4-dione (4), 1-(4-vinylbenzyl)-1??,3??-dihydrospiro[imidazolidine-4,2??-indene]-2,5-dione (5), 1-(4-vinylbenzyl)-3??,4??-dihydro-1??H-spiro[imidazolidine-4,2??-naphthalene]-2,5-dione (6), (two of them are unknown: 5 and 6); (c) macromolecular compounds: poly(chloromethyl-p-styrene) (7), used as reference, and three polymers (two of them are novel) obtained by substitution of hydantoins 1?C3 to poly(methyl-p-styrene) (8?C10). Their thermal properties have been studied by thermogravimetry. It was found that the chemical structure, tautomerization, and intermolecular interaction influence the thermal stability of substrates. The presence of phenyl rings causes the increase of resistance of studied hydantoins. The obtained polymers are characterized by significantly improved thermal stability comparing to poly (chloromethyl-p-styrene). The mechanism of thermal degradation of investigated polymers and explanation of their thermal resistance has been proposed. The relatively high temperatures of glass transition of polymers have been determined by DSC.     

Über Reaktionen mit Betainen, 18. Mitt. Über Betaine und ihre Beziehungen zu N-Yliden. Trifluoracetyl-N-methylide und ihre Beziehungen zu den entsprechenden Ammoniumbasen

The betaines1b–d were prepared⁴ by systematic variation of the alkyl groups and were reacted with trifluoroacetic acid anhydride (TFA) to give the diacyl-ylides2b,c. The betain1d andTFA afford the trifluoroacetate3d ⁵. The salts3b,c, which result from hydrolysis of2b,c as well as3d (X=I) can be transformed in 75 to 83% yield into the monoacyl-ylides4b–d with the help of silver oxide. Aqueous solutions of4a–d exhibit alkalinepH, which points to the formation of the corresponding ammonium bases. In the case of4b,c the bases5b,c could be isolated. It can be shown, that4b,c and5b,c, respectively, undergo a reversible addition or elimination of one mole wather with great ease.     

Synthesis and crystal structure of complexes of manganese(II), cobalt(II), and nickel(II) isothiocyanates with ?-caprolactam

The possibility of ?-caprolactam (CPL) to coordinate to manganese(II), cobalt(II), and nickel(II) rhodanides has been investigated. New complexes trans-[M(CPL)₄(NCS)₂], where M = Mn (I), Co (II), and Ni (III), have been synthesized. The complexes have been studied by chemical analysis and IR spectroscopy. According to X-ray diffraction, complexes are isostructural to each other and crystallize in monoclinic space group P2₁/c, Z = 2. For I: a = 6.9457(2) ?, b = 17.7751(6) 0A, c = 12.8999(4) 0A, ?? = 104.2670(10)°, V = 1543.51(8) ?³, ??_calc = 1.342 g/cm³, R ₁ = 0.0426. For II: a = 6.8925(2) ?, b = 17.8189(8) ?, c = 12.7278(6) ?, ?? = 104.421(2)°, V = 1513.93(11) ?³, ??_calc = 1.377 g/cm³, R ₁ = 0.0280. For III: a = 6.7804(2) ?, b = 18.4631(4) ?, c = 12.4841(3) ?, ?? = 105.2950(10)°, V = 1507.49(7) ?³, ??_calc = 1.382 g/cm³, R ₁ = 0.0273. Structures I?CIII are molecular; the metal atom in each of them coordinates four CPL molecules and two NCS groups via oxygen and nitrogen atoms, respectively.     

Structures and bonding situation of Pb2X2 (X?=?H, F, Cl, Br and I)

Quantum chemical calculations using DFT (BP86) and ab initio methods (MP2, MP4 and CCSD(T)) have been carried out for the title compounds. The nature of the Pb?CPb interactions has been investigated with an energy decomposition analysis. The energy minimum structures of the halogen substituted Pb₂X₂ molecules possess a doubly bridged butterfly geometry A like the parent system Pb₂H₂. The unusual geometry can be explained with the interactions between PbX fragments in the X ²?? ground state which leads to one Pb?CPb electron-sharing ?? bond and two donor?Cacceptor bonds between the Pb?CX bonds as donor and vacant p(??) AOs of Pb. The energy difference between the equilibrium form A and the linear structure XPb??PbX (E) which is a second-order saddle point is much higher when X is a halogen atom than for X?=?H. This is because the a ⁴??^?????X ²?? excitation energies of PbX (X?=?F?CI) are higher than for PbH. The structural isomers B, D1, D2, E, F1, F2 and G of Pb₂X₂ are no minima on the potential energy surface.     

Conformational space of tetrakis(2-naphthalenyl)ethene: a naphthologous AIE luminogen

The AIE luminogen tetrakis(2-naphthalenyl)ethene (2-NA ₄ E) was synthesized by Barton’s double extrusion diazo-thione coupling method from 2,2′-dinaphthyl thioketone and 2,2′-(diazomethylene)bisnaphthylene in 77 % yield. The structure of 2-NA ₄ E was confirmed by its ¹H NMR and ¹³C NMR spectra with full assignments. 2-NA ₄ E and its parent tetraphenylethene (Ph ₄ E) have been subjected to a comprehensive computational DFT study, in search of their conformational spaces. Seven conformers and two transition states of 2-NA ₄ E have been located. Four conformers and one transition state of Ph ₄ E have been located. The conformers of 2-NA ₄ E and Ph ₄ E are not overcrowded, as indicated by the contact distances in the fjord and cove regions. The relative free energies (ΔG ₂₉₈) of the six most stable conformers of 2-NA ₄ E are in the narrow range of 2.3 kJ/mol; they make comparable contributions (12–29 %) to the equilibrium mixture. The energy barriers for the diastereomerization D ₂-Z,Z,Z,Z $ \rightleftharpoons $ ? D ₂-E,E,E,E via the transition state C ₁-Z,E,E,Z and for the enantiomerization C ₂-Z,Z,E,E $ \rightleftharpoons $ ? C ₂-E,E,Z,Z via the transition state C _i -Z,E,Z,E are only 29.8 and 29.0 kJ/mol, respectively, indicating very rapid rates of diastereomerization and enantiomerization at room temperature. The values of naphthalenyl torsion angles and ethenic twist angles in 2-NA ₄ E are almost identical to those in the parent Ph ₄ E. The previously proposed “bulkiness” of the naphthalenyl substituents and the validity of the restriction of naphthalenyl rotation are challenged. The analysis of the AIE effect in 2-NA ₄ E should take into account the intermolecular homochiral and heterochiral interactions between the conformers.     

Three-dimensional supramolecular architecture based on 4,4′-methylene-bis(benzenamine) and aromatic carboxylic acid guests: Synthons cooperation, robust motifs and structural diversity

The two-component solid forms involving 4,4??-methylene-bis(benzenamine) included both salts and co-crystals, while 4,4??-methylene-bis(benzenamine) crystallized exclusively as a salt, in agreement with the differences in the pK _a values. Many of the crystal structures displayed either the neutral or the ionic form of the carboxylic acid-amino heterosynthon, and the similarity in crystal structures between the neutral and the ionized molecules makes the visual distinction between a salt and co-crystal dependent on the experimental location of the acidic proton. A variety of supramolecular hydrogen bonded motifs involving interactions between the aza molecules and carboxylic acid groups are observed rather than just the O-H??N/O-H??O motif. The motifs are identical in all the two compounds analyzed showing the robustness of these supramolecular synthons. In all adducts, recognition between the constituents is established through either N-H??O and/or O-H??O/O-H??N pairwise hydrogen bonds. In all adducts, COOH functional groups available on 1 and 2 interact with the N-donor compounds. The COOH moieties in 1 forms only single N-H??O hydrogen bonds, whereas in 2, it forms pairwise O-H??N/N-H??O hydrogen bonds. The supramolecular architectures are elegant and simple, with stacking of networks in 2, but a rather complex network with a threefold interpenetration pattern was found in 1. Thermal stability of these compounds has been investigated by thermogravimetric analysis (TGA) of mass loss.     

New copper(II) 2-(alkylamino)troponates

The copper aminotropones Cu[ON(R′)C₇H₄R-4]₂ [R = H, R′ = Me (13), Et (14), n-Pr (15), n-Bu (16), Bz (17), MenOCH₂CH₂ (20); R = i-Pr, R′ = Me (18), n-Pr (19), MenOCH₂CH₂ (21)] have been prepared from the corresponding aminotropones HN(R′)OC₇H₄R-4 (1–7) by reacting with copper(II) acetate in aqueous ethanol. 20, 21 contain the flavourant, menthol, as part of the ligand. The structures of 5 (R = H, R′ = Bz), a hydrogen-bonded dimer, 14 and 20, both incorporating square-planar, four-coordinate copper centres, have been determined by X-ray crystallography. The antibacterial activities of complexes 13, 17, 20 and 21 have been assayed against Staphylococcus waneri, an in vitro model of plaque inhibition effects, and found to be more active than a commercial toothpaste formulation, but less active than the O,O-chelated copper(II) complex of ethylmaltol.     

Synthesis and crystal structure of the complex N,N-dimethylanilinium dicitratoborate monohydrate

N,N-Dimethylanilinium dicitratoborate monohydrate [C₆H₅NH(CH₃)₂][(C₆H₆O₇)₂B]·H₂O (I) was synthesized for the first time. Single crystals were obtained in an aqueous solution; the crystal structure was studied by X-ray crystallography. Crystals of I are triclinic, space group $P\bar 1$ , a = 9.7017(2) ?, b = 11.0475(2) ?, c = 12.6282(2) ?, ?? = 106.595(2)°, ?? = 106.931(1)°, ?? = 103.568(1)°, V = 1163.97(4) ?³, Z = 2, ??_calc = 1.516 g/cm³. The structural units of compound 1 are large complex dicitratoborate anions with a spiran structure, N,N-dimethylanilinium cations, and crystal water molecules. The crystal packing is a three-dimensional framework. A hydrogen-bond system is formed by seven independent contacts O(N)-H??O.     

Synthesis and crystal structures of Zn(II) complexes with N,N′-bis[(1-(2-pyridyl)ethylidene)propane-1,3-diamine and N,N′-bis[(1-(2-Pyridyl)ethylidene)ethane-1,2-diamine1

Two new zinc complexes, [Zn(Ppd)I]ClO₄ (I) and [Zn(Ped)I]ClO₄ (II), where Ppd and Ped are the Schiff bases N,N??-bis[(1-(2-pyridyl)ethylidene)propane-1,3-diamine and N,N??-bis[(1-(2-pyridyl)ethylidene)ethane-1,2-diamine, respectively, have been synthesized and characterized by means of elemental analysis, infrared spectroscopic, molar conductivity, and single crystal X-ray diffraction. The crystal of I is tri-clinic: space group $P\bar 1$ a = 8.421(2), b = 9.143(2), c = 13.166(3) ?, ?? = 92.521(5)°, ?? = 94.498(3)°, ?? = 94.232(4)°, V = 1006.6(4) ?³, Z = 2. The crystal of II is triclinic: space group $P\bar 1$ , a = 8.219(1), b = 8.483(1), c = 14.733(2) ?, ?? = 80.058(1)°, ?? = 81.960(1)°, ?? = 89.300(1)°, V = 1001.8(2) ?³, Z = 2. The zinc atom in the complexes assumes a distorted square pyramidal geometry through coordination by two pyridine N atoms and two imine N atoms of the Schiff base at the basal plane, and by a I atom at the apical position.     

Design, synthesis, and cytotoxicity of 4-sulfonamide substituted benzamidobenzimidazolones and an acyl benzimidazolone

4-Sulfonamide substituted benzamidobenzimidazolones were designed and docked into the active site model of CDK2, using an oxindole inhibitor as the template. Compounds 6a-6i were then prepared from the reaction of the sulfonyl chloride 1 with different amines to give the corresponding acids (2a-2i), which were converted to their corresponding acyl chlorides (3a-3i). Reaction of 3a-3i with o-nitrophenylhydrazine afforded the respective nitro derivatives (4a-4i). The nitro groups were then reduced to give the corresponding amines (5a-5i), which, upon reaction with ethyl chloroformate, the target compounds (6a-6i) were produced. Target benzimidazolone derivatives (9a-9e) were also prepared from the reaction of isopropenyl benzimidazolone (8) with different sulfonyl or acyl chlorides. The target compounds were then tested by a modified 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay against the cancer cell lines, Hep G2, HT-29, CL1-5 and AGS. Despite similar binding properties of the flexible benzamidobenzimidazolones and rigid cytotoxic oxindole inhibitors at the active site of CDK2, biological screening results indicated that benzamidobenzimidazolones did not exhibit significant cell growth inhibition in vitro. Their analogue, 3-acyl benzimidazolone (12), however, revealed cytotoxicity similar to that of the reference oxindole inhibitor.     

Synthesis of some new α,α-dioxoketene-N,S- and -N,N-acetals derived from secondary aliphatic amines

A total of 11 new α,α-dioxoketene- N,S -acetals (2a–2k) and two new α,α-dioxoketene- N,N -acetals (3j and 3k) have been synthesised by treating 3-[bis(methylthiol)methylene]pentane-2,4-dione (1) with increasing mole ratios of secondary aliphatic amines at room temperature, in either toluene or ethanol. Eight non-cyclic N -methylalkyl and N -ethylalkyl amines and the azacyclopentane of pyrrolidine yielded exclusively mono-substituted N,S -acetals (2a–2i), while the azacyclohexanes of piperidine and morpholine yielded the mono-substituted N,S -acetals 2j and 2k and the double-substituted N,N -acetals 3j and 3k. The conversion yields for the reactions in ethanol are considerably higher than those in toluene. Furthermore, the secondary aliphatic amines with an N -methylalkyl moiety, which have one primary α-carbon and less steric crowding around the nucleophilic nitrogen, appear to be more reactive towards 1 than those with the N -ethylalkyl group, which have two primary α-carbons; further, the latter amines are more reactive than the amines with secondary α-carbons.     

Three-dimensional molecular reconstruction of rat heart with mass spectrometry imaging

Cardiovascular diseases are the world’s number one cause of death, accounting for 17.1 million deaths a year. New high-resolution molecular and structural imaging strategies are needed to understand underlying pathophysiological mechanism. The aim of our study is (1) to provide a molecular basis of the heart animal model through the local identification of biomolecules by mass spectrometry imaging (MSI) (three-dimensional (3D) molecular reconstruction), (2) to perform a cross-species validation of secondary ion mass spectrometry (SIMS)-based cardiovascular molecular imaging, and (3) to demonstrate potential clinical relevance by the application of this innovative methodology to human heart specimens. We investigated a MSI approach using SIMS on the major areas of a rat and mouse heart: the pericardium, the myocardium, the endocardium, valves, and the great vessels. While several structures of the heart can be observed in individual two-dimensional sections analyzed by metal-assisted SIMS imaging, a full view of these structures in the total heart volume can be achieved only through the construction of the 3D heart model. The images of 3D reconstruction of the rat heart show a highly complementary localization between Na⁺, K⁺, and two ions at m/z 145 and 667. Principal component analysis of the MSI data clearly identified different morphology of the heart by their distinct correlated molecular signatures. The results reported here represent the first 3D molecular reconstruction of rat heart by SIMS imaging.