Within the framework of PM3 molecular orbital approximation the thermodynamic function characteristics for the formation and geometrical structure of monomers, dimers, trimers, and tetramers of nondissociated n-carboxylic acids C(n)H(2n+1)COOH with n = 5-15 are calculated. It is shown that spontaneous aggregation of homologous fatty acids for the homologues with carbon atoms numbers n > or = 13 at the air/water interface can take place, leading to the formation of infinite plane rectangular clusters, whereas for the homologues with n < 11 spontaneous decomposition of large aggregates is energetically preferable. At the same time, the formation of trimers is more probable for the lower homologues (8 < n < 13). These results agree well both with the experimental data reported by various authors and with thermodynamic models developed earlier for soluble and insoluble monolayers. The slopes of the regressions calculated for the dependencies of the thermodynamic parameters on the alkyl chain length for all the clusters considered are all equal to each other. This fact indicates that the contributions of the CH2 groups to the thermodynamic characteristics of alcohols and acids are the same, and the differences in the formation of clusters by these substances should be attributed only to the differences in the structure and interactions of relevant functional groups. Therefore, it enables one to describe both acids and alcohols within the framework of the developed method, and it makes it possible to extend the proposed approach onto other classes of amphiphilic compounds.

Triple-decker complexes with a bridging diborolyl ligand CpCo(µ-1,3-C 3 B 2 Me 5 )M(ring) (M(ring) ) RuCp, 4; RuCp*, 5; Co(C 4 Me 4 ), 6) were synthesized by electrophilic stacking of the sandwich anion [CpCo(1,3-C 3 B 2 Me 5 )]with the [(ring)M(MeCN) 3 ] + cations. Structures of 4-6 were confirmed by X-ray diffraction. The electrochemical and spectroelectrochemical behavior of the complexes prepared was studied. DFT calculations of the redox potentials were also performed. Similar bonding properties of anions [CpCo(1,3-C 3 B 2 R 5 )]and [C 5 R 5 ] -(R ) H, Me) toward [M(ring)] + cations were established both experimentally (synthesis, electrochemistry, and X-ray diffraction) and theoretically (energy decomposition and Mulliken population analysis).

On the basis of the 1,2,3,4-tetrahydrofluorenyl ligand, a simple approach was developed to new effective rhodium catalysts for the construction of CÀ C and CÀ N bonds. The halide compounds [(η 5 -tetrahydrofluorenyl)RhX 2 ] 2 (2 a: X = Br; 2 b: X = I) were synthesized by treatment of the bis (ethylene) derivative (η 5 -tetrahydrofluorenyl)Rh(C 2 H 4 ) 2 (1 a) with halogens. An analogous reaction of the cyclooctadiene complex (η 5 -tetrahydrofluorenyl)Rh(cod) (1 b) with I 2 is complicated by the side formation of [(cod)RhI] 2 . The reaction of 2 b with 2,2'-bipyridyl leads to cation [(η 5 -tetrahydrofluorenyl) Rh(2,2'-bipyridyl)I] + (3). The halide abstraction from 2 a,b with thallium or silver salts allowed us to prepare sandwich compounds with incoming cyclopentadienyl, dicarbollide and mesityleneligands [(η 5 -tetrahydrofluorenyl)RhCp] + (4), (η 5 -tet-rahydrofluorenyl)Rh(η-7,8-C 2 B 9 H 11 ) (5), and [(η 5 -tetrahydrofluorenyl)Rh(η-mesitylene)] 2 + (6). The structures of 1 b, 2 b • 2I 2 , 3PF 6 , 4TlI 4 , 5, and [(cod)RhI] 2 were determined by X-ray diffraction. Compounds 2 a,b efficiently catalyze the oxidative coupling of benzoic acids with alkynes to selectively give isocoumarins or naphthalenes, depending on the reaction temperature. Moreover, they showed moderate catalytic activity in other annulations of alkynes with aromatic compounds (such as benzamide, acetanilide, etc.) which proceed through CH activation. Compound 2 b also effectively catalyzes the reductive amination of aldehydes and ketones in the presence of carbon monoxide and water via water-gas shift reaction, giving amines in high yields (67-99 %).

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Thirty‐valence‐electron dicationic triple‐decker complexes with a bridging borole ligand [CpRh(μ‐η5:η5‐C4H4BPh)M(ring)]2+ [M(ring) = CoCp* (3), IrCp* (6), Ru(η‐C6H3Me3‐1,3,5) (8a), Ru(η‐C6Me6) (8b)] were obtained by stacking reactions of [CpRh(η5‐C4H4BPh)] (2) with the corresponding half‐sandwich fragments [M(ring)]2+. Minor formation of arene‐type complexes [CpRh(μ‐η5:η6‐C4H4BPh)M(ring)]2+ was observed for M(ring) = IrCp* and Ru(arene). On the contrary, the arene‐type complex [CpRh(μ‐η5:η6‐C4H4BPh)RhCp*]2+ (5) was isolated as the sole product from the reaction of 2 with the fragment [RhCp*]2+; an intermediate formation of the triple‐decker complex [CpRh(μ‐η5:η5‐C4H4BPh)RhCp*]2+ (4) in this reaction was detected by 1H NMR spectroscopy. Heating 6 in nitromethane gives the symmetrical triple‐decker complex [Cp*Ir(μ‐η5:η5‐C4H4BPh)IrCp*]2+ (10). The cations were isolated as salts with the BF4– anion. The structures of 2, 5(BF4)2, 6(BF4)2 and 8a(BF4)2 were determined by X‐ray diffraction. The electrochemical properties of the complexes were also investigated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

An efficient protocol was developed for the synthesis of π‐extended isocoumarins and polycyclic aromatic hydrocarbons based on the oxidative coupling of aromatic carboxylic acids with internal alkynes catalyzed by (cyclopentadienyl)rhodium complexes. The coupling chemoselectivity strongly depends on whether Cp or the methylated Cp* ligands are used. The pentamethyl derivative [Cp*RhCl2]2 predominantly gives isocoumarins, while the non‐methylated complex [CpRhI2]n produces naphthalene derivatives. The polyaromatic carboxylic acids (such as 1‐naphthoic acid, 1‐pyrenecarboxylic acid, fluorene‐1‐carboxylic acid, and dibenzofuran‐4‐carboxylic acid) are suitable for this approach. A mixture of Cp*H/RhCl3 can be used as a catalyst instead of [Cp*RhCl2]2. The structures of 3,4‐diphenylindeno[1,2‐h]isochromen‐1(11H)‐one and 7,10‐dimethyl‐8,9‐diphenylbenzo[pqr]tetraphene were determined by X‐ray diffraction. In addition, the optical properties of the prepared compounds were studied. 7,8‐Diphenyl‐10H‐phenaleno[1,9‐gh]isochromen‐10‐one was employed as an emissive layer for OLED manufacturing. The OLED emits yellow‐green light with a maximum intensity 1740 cd ⋅ m−2 at 15 V.

Efficient protocols for the synthesis of triphenylcyclopentadienyl rhodium halides [(1,2,4-C5Ph3H2)RhX2]2 (1a,b: X = Cl, I) starting from 1,2,4-triphenylcyclopentadiene or the cyclooctadiene derivative (1,2,4-C5Ph3H2)Rh(cod) (2) were developed. Iodide abstraction from 1b with thallium or silver salts allowed us to prepare rhodocenium [(1,2,4-C5Ph3H2)RhCp]PF6 (3PF6) and mesitylene complex [(1,2,4-C5Ph3H2)Rh(mesitylene)](SbF6)2 (4(SbF6)2). Halides 1a,b (at 0.5 mol % loading) showed high catalytic activity in the construction of C–C, C–O, and C–N bonds via the C(sp2)–H activation approach. Their efficiency was demonstrated in the synthesis of more than 40 examples of polycyclic organic compounds (such as isocoumarins and naphthalenes, as well as isoquinolinium and dibenzo[a,f]quinolizinium salts). The protocols developed tolerate a wide range of functional groups. In particular, they were successfully used for the atom- and step-economical synthesis of hydroxy-substituted isocoumarins, including the natural product oospalactone 7fe. The 6- or 8-hydroxy-substituted isocoumarins showed moderate antiproliferative activity against several human cell lines in vitro.

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