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The novel tetrahedral [Bi(5)(dpd)(6) within CH(3)CN](ClO(4))(3).3CH(3)CN (dpd = di-2-pyridyl-gem-diolate) has been synthesized from [Bi(9)(mu(3)-O)(8)(mu(3)-OH)(6)](ClO(4))(5) and di-2-pyridyl ketone. The Bi(5) complex incorporates CH(3)CN via C-HO hydrogen bonding.

Four new decarestrictine analogues (botryolides A-D; 1- 4), a biosynthetically related gamma-lactone (botryolide E; 5), and the known compounds decarestrictine D ( 6) and sterigmatocystin have been isolated from cultures of a fungicolous isolate of Botryotrichum sp. (NRRL 38180). The structures of these compounds were determined by analysis of 2D NMR and ESIMS data. The relative configurations of 1- 5 were established on the basis of NMR data and/or X-ray diffraction analysis, while the absolute configuration of 1 was assigned using the modified Mosher method.

We describe a heteromolecular single crystal that exhibits three reversible and concerted reorganizations upon heating and cooling. The products of the reorganizations are conformational polymorphs. The reorganizations are postulated to proceed through three motions: (i) alkyl translations, (ii) olefin rotations, and (iii) rotational tilts. The motions are akin to rack-and-pinion gears at the molecular level. The rack-like movement is based on expansions and compressions of alkyl chains that are coupled with pinion-like 180 degree rotations of olefins. To accommodate the movements, phenol and thiophene components undergo rotational tilts about intermolecular hydrogen bonds. The movements are collective, being propagated in close-packed repeating units. This discovery marks a step to understanding how organic solids can support the development of crystalline molecular machines and devices through correlated and collective movements.

Decaspirones A-E (1-5), five new compounds related to the palmarumycins, were isolated from cultures of the freshwater aquatic fungal species Decaisnella thyridioides. The known compound palmarumycin CP1 (6) was also obtained. The structures of 1-5 were determined by analysis of NMR and MS data, and their relative configurations were assigned by analysis of 1H NMR J-values and NOESY data. The structure of the lead compound 1 was confirmed by X-ray crystallographic analysis. Compounds 1-5 possess a trans ring fusion not previously reported in members of this structural class. The absolute configuration of 1 was assigned using the modified Mosher method. Compounds 1-5 showed potent antifungal and antibacterial activity.

[Structure: see text] Cultures of the freshwater aquatic fungus Helicodendron giganteum afforded three new compounds, heliconols A-C (1-3), that contain an unusual reduced furanocyclopentane unit. The structures of these metabolites were assigned by analysis of 1D and 2D NMR data. The absolute configuration of heliconol A (1) was assigned by single-crystal X-ray crystallographic analysis of its dibromobenzoate derivative. Heliconol A showed antifungal and antibacterial activities in disk diffusion assays.

[structure: see text] Penifulvin A (1), a new fungal metabolite with a previously undescribed ring system, has been isolated from cultures of an isolate of Penicillium griseofulvum (NRRL 35584) obtained from a white mycelial growth on a dead hardwood branch collected in a Hawaiian forest. The structure was assigned by analysis of NMR data and confirmed by single-crystal X-ray diffraction analysis. Penifulvin A (1) shows significant activity in dietary assays against the fall armyworm Spodoptera frugiperda.

(C5Me5R)2Ta2Cl4 (d2-d2) disproportionates under dinitrogen to [(C5Me4R)TaCl2]2(mu-N2) and the D3h cluster cation (C5Me4R)3Ta3(mu-Cl)6+ with anionic (C5Me4R)TaCl4-.

Base hydrolysis of BiO(ClO4) yields ClO4- salts of the novel nonabismuth polyoxo cation Bi9(mu3-O)8(mu3-OH)6(5+); ethanolysis converts to the ethoxide Bi9(mu3-O)8(mu3-OEt)6(5+).

Malettinins B-D (2-4), three new antimicrobial polyketide-derived metabolites related to the previously reported malettinin A (1), have been obtained from nonsporulating cultures of an isolate of Mycelia sterilia MYC-155 (= NRRL 29110) collected from colonies of Hypoxylon stromata. Malettinins B (2) and C (3) are partially reduced analogues of malettinin A and were identified by analysis of NMR and MS data. Malettinin D (4) is biogenetically similar, but possesses a new ring system, and the structure of 4 was established by single-crystal X-ray diffraction analysis.

Derivatized s-triazine (C3N3) precursors have seen significant recent use in the production of carbon nitride materials. Larger polycyclic molecular precursors, such as those containing an s-heptazine core (C6N7 or tri-s-triazine), may improve stability and order in carbon nitride products. In this Communication, we describe the synthesis and crystal structure of 2,5,8-triazido-s-heptazine (2). Synthesis of 2 was achieved from melon, an oligomeric s-heptazine synthesized by the pyrolysis of NH4SCN. Melon was converted to molecular 2,5,8-trichloro-s-heptazine, which was then transformed to the triazide upon reaction with (CH3)3SiN3. The crystal structure of 2 verifies that the s-heptazine is planar and the azides adopt a pinwheel-like C3h arrangement around the periphery. The s-heptazine core shows pi delocalization in the C-N bonds around the periphery (av. 1.33 A), while the internal planar C-N bonds are longer (1.40 A). The heptazine units pack into parallel, but offset, layered sheets in the crystal. The triazide 2 exhibits photoluminescence at 430 nm and rapidly and exothermically decomposes upon heating at 185 degrees C to produce a tan thermally stable carbon nitride powder with a formula near C3N4.

15-Deoxyoxalicine B (1) and decaturins A (2) and B (3) have been isolated from Penicillium decaturense and Penicillium thiersii, two previously undescribed species obtained as colonists of wood-decay fungi. The structures were determined by 2D NMR experiments and/or single-crystal X-ray diffraction analysis. These compounds are members of a rare structural class, and decaturins A and B feature a new polycyclic ring system. Decaturin B (3) exhibited potent antiinsectan activity against the fall armyworm (Spodoptera frugiperda).

Reduction of the organoditantalum allene complex (eta-C5Me4R)2Ta2(mu-X)X3(mu-eta1,eta3-C3H4) (R = Me (Cp*), Et; X = Cl, Br) with sodium amalgam leads to the propynylidene complex (eta-C5Me4R)2Ta2(mu-H)2X2(mu-HCCCH) by a formal double 1,3-C-H activation of the allene ligand. The solid-state molecular structure contains a planar HCCCH ligand bridging, in parallel coordination mode, the two tantalum atoms, with the HCCCH and Ta atoms coplanar. Key structural features are a Ta-Ta distance of 2.8817(7) A, propynylidene C-C-C angle of 153.7(13) degrees , C-C distance of 1.370(8) A, Ta-C(central) distance of 2.194(9) A, and Ta-C(terminal) distance of 1.970(9) A. Molecular orbital calculations on the complex at the RHF/SBK(d) and B3LYP/LanL2dz levels of theory demonstrate that the propynylidene ligand is best viewed formally as an allenediylidene(4-) ligand bonded to two d0 tantalum atoms via two Ta=C(terminal) double bonds and an unusual three-center, two-electron bridge bond involving both tantalum atoms and a lone pair on the planar, tetracoordinate central carbon. There is no net Ta-Ta bonding based on the orbital analysis.

Four new rosigenin analogues (massarigenins A-D; 1-4) and two new aromatic polyketide-derived secondary metabolites (massarinins A and B; 6, 7) and have been isolated from the freshwater aquatic fungus Massarina tunicata. The structures of these compounds were determined primarily by analysis of NMR data, and that of compound 1 was verified by X-ray crystallography. The known compound 4-(2-hydroxybutynoxy)benzoic acid (11) was also obtained, and its absolute stereochemistry was assigned. Several of these metabolites showed antibiotic activity against Gram-positive bacteria.

(+-)-Tartaric acid, C(4)H(6)O(6), crystallized from ethanol in space group P 1 macro. The structure is characterized by five hydrogen bonds, including the formation of a centrosymmetric carboxylic acid dimer which forms infinite chains along the body diagonal. These chains form sheets via hydrogen bonding between alpha-hydroxyl groups. The sheets are connected through a bifurcated hydrogen bond. Structural comparisons are made with homochiral (2R,3R)-(+)-tartaric acid.