Crystal Structures Of 1a Research Articles

Synthesis and characterisation of neutral and cationic alkyl aluminium complexes bearing N,O-Schiff base chelates with pendant donor arms

The Schiff base ligands [3,5-But2-2-(OH)C6H2CHNL] [L = CH2CH2NMe2 (1a), 2-(PhO)C6H4 (1b), 2-CH2C5H3N (1c), 8-C9H6N (quinoline) (1d) and 2-(PPh2)C6H4 (1e)] are accessed in good yields (>85%) via standard imine condensation reactions. Reaction of 1a–e with Me3Al at room temperature affords the corresponding complexes [(3,5-But2-2-(O)C6H2CHNL)AlMe2] (2a–e); in the case of L = 8-quinoline, the same reaction conducted in refluxing toluene affords binuclear {[3,5-But2-2-(O)C6H2CHMeN-8-C9H6N]AlMe}2 (3) by methyl migration from metal to ligand. Further reaction of the dimethyl compounds with B(C6F5)3 in CD2Cl2 or C6D6 affords the cationic systems [(3,5-But2-2-(O)C6H2CHNL)AlMe]+ (4a–e). The crystal structures of 2a, 2c, 2e and 3 have been determined. In 2a and 2c the respective ligands bind to the metal centre via all three heteroatoms, the aluminium having a trigonal bipyramidal geometry, whereas in 2e coordination is via nitrogen and oxygen only, and the aluminium is tetrahedral. Complex 3 has a dimeric structure with the ligand adopting both tridentate and binucleating roles; the aluminium centres are trigonal bipyramidal.

Synthesis and Reactivity toward Isonitriles of (2-Aminoaryl)palladium(II) Complexes

Mixtures of “Pd(dba)2” (dba = dibenzylideneacetone) and 2,2‘-bipyridine (bpy; 1:2) or N,N,N‘,N‘-tetramethylethylenediamine (tmeda; 1:1) react with 2-bromo-4-nitroaniline to give [Pd{C6H3NH2-2-NO2-5}Br(N−N)] (N−N = bpy (1b), tmeda (1b‘)). Reactions of 2-iodoaniline with mixtures of “Pd(dba)2” and isonitriles RNC (R = C6H3Me2-2,6 (Xy), 2:1:2 molar ratios; R = tBu, 2.9:1:2 molar ratios) result in the formation of the complexes [Pd{κ2C,N-C(NXy)C6H4NH2-2}I(CNXy)] (2a) and trans-[Pd{C(NtBu)C6H4NH2-2}I(CNtBu)2] (3a*). The reactions of [Pd{C6H4NH2-2}I(bpy)] and 1b‘ with RNC give the complexes trans-[Pd{C(NR)C6H3NH2-2-Y-5}}X(CNR)2] (Y = H, X = I, R = Xy (3a), tBu (3a*); Y = NO2, X = Br, R = Xy (3b), tBu (3b*)). Complexes 3 react with Tl(TfO) (TfO = CF3SO3) to give decomposition products, with the exception of 3a, which gives the cyclopalladated complex cis-[Pd{κ2C,N-C(NXy)C6H4NH2-2}(CNXy)2]TfO (4a). Complex 2a or 3 reacts with Tl(TfO) in the presence of the corresponding ligand, L or L2, to give the cationic complex [Pd{C(NR)C6H3NH2-2-Y-5}(CNR)L2]TfO (L = tBuNC, Y = H (5a*), NO2 (5b*); L2 = bpy, Y = H, R = Xy (6a), tBu (6a*)). When L = PPh3, the resulting complexes trans-[Pd{C(NR)C6H3NH2-2-Y-5}(CNtBu)2(PPh3)]TfO (Y = H (7a*), NO2 (7b*)) decompose easily to the Pd(I) complex [Pd2(CNtBu)4(PPh3)2](TfO)2 (8). The reaction of 2a with Tl(TfO) affords [{Pd[κ2C,N-C(NXy)C6H4NH2](CNXy)}2(μ-I)]TfO (9a), and that with a mixture of bpy and Tl(TfO) in acetone with subsequent bubbling of CO through the solution gives [Pd(R)(CNXy)(bpy)](TfO)2 (10), where R is 2-(xylylamino)-3-xylylquinazolinium-4-yl. The crystal structures of 2a, 3a, 4a, 6a, 8, 9a·CH2Cl2, and 10·1.5CH2Cl2 have been determined by X-ray diffraction studies. Some hydrogen bond interactions (Csp3−H···Pd, N−H···π−arene, N−H···I−Pd; eight-membered rings ···O−S−O···H−N−C−C−H··· and ···I−Pd−N−H···I−Pd−N−H···) lead to interesting supramolecular structures.

Synthesis and conformational dynamics of ortho-xylyl-bridged-[4]cavitands

ortho-Xylyl-[4]cavitands 2 to 6 were synthesized from bromoresorcin[4] arenes 1 . Cavitands 2 to 6 show C 4 v symmetry in their 1H NMR spectra at higher temperatures. Dynamic 1H NMR studies of 2 to 6 indicate the C 4 v symmetry is due to fast interconversion of rectangular C 2 v isomers. This is supported by the crystal structure of 2a , which shows a C 2 v rectangular structure. The activation energy barriers for 2a and 2b were measured by quantitative 1D NOESY (EXSY) experiments. The results were analyzed by the initial rate approximation and matrix calculations. The activation energy barrier was found to depend strongly on the size of the upper rim group (Br, H, OH, CN). In addition, replacing the phenolic proton of tetrol derivatives 4a and 4b with metal ions raises the energy barrier further, likely via bridging metal cations. The two tetrabromo compounds ( 2a and 2b ) reveal a sensitivity of the activation barrier to the feet of the cavitands. Cavitand 6 may act as a hub for radially expanded cavitands. The advantages of the 1D NOESY experiments over the more commonly used two-dimensional experiments are discussed.

Alkynethiolato and alkyneselenolato ruthenium half-sandwich complexes: synthesis, structures, and reactions with (eta(5)-C(5)H(5))(2)Zr.

Alkynethiolato and alkyneselenolato complexes of ruthenium, CpRu(PPh(3))(2)(EC(triple bond)CR) (Cp = eta(5)-C(5)H(5); E = S, R = Ph (1a), SiMe(3) (1b), (t)Bu (1c); E = Se, R = Ph (2a), SiMe(3) (2b)), were synthesized by the reactions of CpRuCl(PPh(3))(2) with corresponding lithium alkynechalcogenolates in THF. An analogous reaction of Cp*RuCl(PEt(3))(2) (Cp* = eta(5)-C(5)Me(5)) with LiSC(triple bond)CPh produced Cp*Ru(PEt(3))(2)(SC(triple bond)CPh) (3). Complexes 1a and 2a were allowed to react in THF with "Cp(2)Zr", generated in situ from Cp(2)ZrCl(2) and 2 equiv of n-BuLi, from which the S-bridged Ru-Zr dinuclear complexes CpRu(PPh(3))(C(triple bond)CPh)(mu-S)ZrCp(2) (4a) and CpRu(PPh(3))(C(triple bond)CPh)(mu-Se)ZrCp(2) (4b) were isolated, respectively. In these complexes, C-S(Se) bond cleavage of the alkynechalcogenolate ligands was promoted by "Cp(2)Zr", and the Zr atom was oxidized from II to IV. Treatment of 4a and 4b in THF under 1 atm CO gave rise to CpRu(CO)(C(triple bond)CPh)(mu-E)ZrCp(2) (E = S (5a), Se (5b)), while addition of tert-butyl isocyanide to a THF solution of 4b afforded CpRu(CN(t)()Bu)(C(triple bond)CPh)(mu-Se)ZrCp(2) (6). The crystal structures of 1a, 1c, 2a, 2b, 3, 4a, 4b, and 5b were determined by X-ray diffraction analysis.

Open-Framework Borophosphates: (NH4)0.4FeII0.55FeIII0.5(H2O)2[BP2O8]·0.6H2O and NH4FeIII[BP2O8(OH)

Two open-framework ammonium−iron borophosphates, black colored (NH4)0.4FeII0.55FeIII0.5(H2O)2[BP2O8]·0.6H2O (1a) (pale gray colored 1b with a powder X-ray diffraction pattern indicating an isotype relationship was also observed) and pale pink colored NH4FeIII[BP2O8(OH)] (2), were synthesized under mild hydrothermal conditions at 180 °C. Their crystal structures were determined by single-crystal X-ray investigations (hexagonal, P65 (no. 170), a = 9.483(4) Å, c = 15.697(5) Å, V = 1222.5(8) Å3, and Z = 6 for 1a and monoclinic P21/c (no. 14), a = 9.370(1) Å, b = 8.309(2) Å, c = 9.680(1) Å, β = 102.05(1)°, V = 737.0(2) Å3, and Z = 4 for 2, respectively). The crystal structure of 1a is characterized by corner-sharing PO4 and BO4 tetrahedra, leading to infinite helical {[BP2O8]3-} ribbons, which are connected by FeII/IIIO4(H2O)2 coordination octahedra. An additional trigonal bipyramidal FeII/IIIO2(H2O)3 coordination polyhedron shares common corners and edges with three FeII/IIIO4(H2O)2 coordination octahedra, leading to tetrameric units. Helical channels, running along [001], are statistically occupied by H2O molecules and NH4+ ions. The structure of 2 is characterized by an infinite {[BP2O8(OH)]4-} chain, which is further connected by FeIIIO4(H2O)2 coordination octahedra leading to one-dimensional channels which are occupied by NH4+ ions. The magnetic properties of both compounds are presented. For compound 1a (and 1b), the mixed-valence state of iron was confirmed. The susceptibility of compound 2 reveals a stronger magnetic interaction and an antiferromagnetic ordering at 17 K.

Five- and Six-Coordinate Ruthenium(II) Complexes Containing 2-Ph2PC6H4CHNtBu and 2-Ph2PC6H4CH2NHtBu as Chelate Ligands: Synthesis, Characterization, and Catalytic Activity in Transfer Hydrogenation of Ketones

Five- and six-coordinate ruthenium(II) complexes containing imino- and aminophosphines have been prepared by ligand exchange processes. Thus, reactions of [RuCl2(PPh3)3] and [RuCl2(DMSO)4] with 2-Ph2PC6H4CHNtBu (a) lead to [RuCl2(κ2-P,N-2-Ph2PC6H4CHNtBu)(PPh3)] (1a) and trans-[RuCl2(κ2-P,N-2-Ph2PC6H4CHNtBu)(DMSO)2] (2a), respectively. Similarly, reactions with 2-Ph2PC6H4CH2NHtBu (b) afford complexes [RuCl2(κ2-P,N-2-Ph2PC6H4CH2NHtBu)(PPh3)] (5b) and [RuCl2(κ2-P,N-2-Ph2PC6H4CH2NHtBu)(DMSO)] (6b) in good yield. The crystal structures of 1a and 5b have been determined by X-ray diffraction. Compound 2a, containing two labile DMSO ligands, has been used as a precursor to synthesize the derivatives [RuCl2(κ2-P,N-2-Ph2PC6H4CHNtBu)L] [L = PPh3 (1a); PPh2Me (3a); PMe2Ph (4a)]. Complexes 1a, 2a, 5b, and 6b are active in catalytic transfer hydrogenation of aryl−alkyl and dialkyl ketones in propan-2-ol. The five-coordinate complexes 1a, 5b, and 6b show higher catalytic activity than the octahedral complex 2a. Complexes 1a and 5b are more efficient catalysts than the precursor complex [RuCl2(PPh3)3]. For the best catalyst, 1a, yields up to 91% were obtained and turnover frequencies may be as high as 41 400 h-1.

Chiral squaric prolinols: a new type of ligand for the asymmetric reduction of prochiral ketones by borane

A series of chiral bifunctional squaric prolinol ligands, having N, S substituents at C(3) of the squaric ring were synthesized and applied to the asymmetric borane reduction of prochiral ketones via an in situ formed chiral boron heterocycle, affording secondary alcohols with high yields and excellent enantiomeric excesses (up to 99%). The crystal structure of 5a was obtained and the mechanism of the catalytic asymmetric reduction is also discussed.

Synthesis and structural features of complexes [(P∩P)2Rh][hfacac] containing hexafluoroacetyl- acetonate as a noncoordinating anion

The synthesis and characterization of complexes [(P∩P)2Rh][hfacac] (P∩P = chelating bidentate phosphine ligand R2P(CH2)nPR2 (2a-g), hfacac = hexafluoroacetylacetonate anion) (4) is reported. The molecular structures of 4a (R = Ph, n = 1) and 4f (R = Cy, n = 2) in the solid state were determined by single-crystal X-ray diffraction. The complexes crystallize in the monoclinic space groups C2/c (No. 15) and P21/n (No. 14), respectively. No coordinative interaction between the rhodium center of the cation [(P∩P)2Rh]+ (4a+, 4f+) and the hfacac anion is evident in either cases. In the crystal structure of 4a, hydrogen bonds between the oxygen atoms of the hfacac anion and methylene protons of the CH2 bridges of the phosphine ligand lead to highly symmetric chains of regularly alternating cations and anions. The coordination geometry around the rhodium center in 4a+ is ideally square-planar, whereas 4f+ is significantly distorted towards a tetrahedron with an angle between the two P2Rh moieties of 18.6°. The cation 4b+ (R = Cy, n = 1) was investigated in form of the tetrafluoroborate salt for comparison. The compound [{Cy2P(CH2)PCy2}2Rh][BF4] crystallizes as a THF solvate (4b′) in the triclinic space group P[Formula: see text] (No. 2) containing ideally square-planar [(P∩P)2Rh]+ cations. Key words: rhodium, chelating ligands, coordination modes, 1,3-diketonates, phosphorus ligands.

Synthesis and Reactivity of Molybdenum(IV) Olefin Complexes Supported by a Chelating Ancillary Ligand

The reactivity of [Mo(NPh)Cl2(o-(Me3SiN)2C6H4·THF)] (1) with β-hydrogen-containing Grignard reagents was examined. Reaction of 1 with 2 equiv of RMgCl (R = CH2CH2Ph, CH2CH2CH3, CH2CH(CH3)2, CH2CH2CH2CH3, and CH(CH3)CH2CH3) gave Mo(IV) olefin complexes of the type [Mo(NPh)(η2-olefin)(o-(Me3SiN)2C6H4)] (olefin = styrene (2a), propene (2b), isobutene (2c), 1-butene (2d), and 2-butene (2e)). The crystal structure of 2a is reported. Reaction of 1 with 2 equiv of ethylmagnesium chloride afforded a mixture of metallacyclopentane [Mo(NPh)(CH2CH2CH2CH2)(o-(Me3SiN)2C6H4)] (3a) and an oligomeric molybdenum species having the empirical formula [Mo(NPh)(o-(Me3SiN)2C6H4)]x (3b). Pure 3a was obtained by reaction of 1 with 2 equiv of EtMgCl under an atmosphere of ethylene. Treatment of 3a with excess PMe3 in benzene at 80 °C afforded [Mo(NPh)(η2-ethylene)(o-(Me3SiN)2C6H4)(PMe3)2] (3c). Compounds 2c and 2a react with acetone to yield the oxametalacyclopentanes [(Mo(NPh)(C(CH3)2CH2C(CH3)2O)(o-(Me3SiN)2C6H4)] (4a) and [(Mo(...

Mononuclear (Pd, Pt), Heterodinuclear (PdAg, PtAg), and Tetranuclear (Pd2Ag2, Pt2Ag2) 1,1-Ethylenedithiolato Complexes

lp;&-5q;1 The reactions of [Tl2[S2C=C[C(O)Me]2]]n with [MCl2L2] (1:1) or with [MCl2(NCPh)2] and PPh3 (1:1:2) give complexes [M[eta2-S2C=C[C(O)Me]2]L2] [M = Pt, L2 = 1,5-cyclooctadiene (cod) (1); L2 = bpy, M = Pd (2a), Pt (2b), L = PPh3, M = Pd (3a), Pt (3b)] whereas with MCl2 and QCl (2:1:2) anionic derivatives Q2[M[eta2-S2C=C[C(O)Me]2]2] [M = Pd, Q = NMe4 (4a), Ph3P=N=PPh3 (PPN) (4a'), M = Pt, Q = NMe4 (4b)] are produced. Complexes 1 and 3 react with AgClO4 (1:1) to give tetranuclear complexes [[ML2]2Ag2[mu2,eta2-(S,S')-[S2C=C[C(O)Me]2]2]](ClO4)2 [L = PPh3, M = Pd (5a), Pt (5b), L2 = cod, M = Pt (5b')], while the reactions of 3 with AgClO4 and PPh3 (1:1:2) give dinuclear [[M(PPh3)2][Ag(PPh3)2][mu2,eta2-(S,S')-S2C=C[C(O)Me]2]]]ClO4 [M = Pd (6a), Pt (6b)]. The crystal structures of 3a, 3b, 4a, and two crystal forms of 5b have been determined. The two crystal forms of 5b display two [Pt(PPh3)2][mu2,eta2-(S,S')-[S2C=C[C(O)Me]2]2] moieties bridging two Ag(I) centers.

Reaktionen von C(NMe2)4 mit Carbonylverbindungen der 6. Gruppe. Kristallstrukturen von [C(NMe2)3][(CO)5CrC(O)NMe2], [C(NMe2)3]2[Mo2(CO)10] und [C(NMe2)3][(CO)4Mo(O2CNMe2)] / Reactions of C(NMe2,)4 with Group 6 Carbonyl Compounds. Crystal Structures of [C(NMe2 )3 ][(CO)5 CrC(O)NMe2], [C(NMe2)3]2[Mo2(CO)10] and [C(NMe2)3][(CO)4 Mo(O2CNMe2)

Abstract The reaction of C(NMe2)4 (1) with M(CO)6 (M = Cr, W) in THF solution leads to the anionic carbamoyl complexes [C(NMe2)3][(CO)5MC(O)NMe2] (2a, M = Cr; 2c M = W). In the case of M = Mo the resulting complex 2b is not obtained; instead, the salts [C(NMe2)3]2[Mo2(CO)10] (3) and [C(NMe2)3][(CO)4Mo(O2CNMe2)] (4) are isolated. The crystal structures of 2a, 3, and 4 are presented. In the salt-like compounds no interatomic contacts between anion and cation exist, and the cations are disordered. The structure of 4 shows two independent molecules. The compounds were further characterized by IR and NMR spectroscopy.

Structural characterisation of cationic methylallyl, methylindenyl and pentamethylcyclopentadienyl nickel complexes containing the bulky phosphine 1,2-bis(diisopropylphosphino)ethane †

A novel high-yield, convenient synthetic method for the complex [Ni(COD)2] has been developed based upon the use of dibutylmagnesium as reducing agent. The cationic complexes [Ni(η3-CH2C(R)CH2)(dippe)][BPh4] (R = Me 1a or H 1b; dippe = Pri2PCH2CH2PPri2) were obtained by reaction of [Ni(COD)2] with BrCH2C(R)CH2 in diethyl ether, followed by treatment with dippe and NaBPh4 in methanol. [Ni(2-MeInd)(dippe)][BPh4] 2 (2-MeInd = 2-methylindenyl) and [Ni(C5Me5)(dippe)][BPh4] 3 were respectively prepared by reaction of either [Ni(2-MeInd)Br(PPh3)] or [Ni(C5Me5)Br(PPh3)] with dippe and NaBPh4 in methanol. The crystal structures of 1a, 2 and 3 were determined. All of the compounds show pseudo-square planar “two legged” piano stool structures. The methylallyl ligand in 1a shows η3 coordination as expected, whereas in 2 the occurrence of an allyl–ene distortion in the 2-methylindenyl ligand leads to an intermediate η3/η5 coordination mode. An intermediate allyl–ene/diene distortion is present in the C5Me5 ligand in 3, although in this case a symmetrical η5 coordination is observed. All compounds were also characterised in solution by NMR spectroscopy.

Reactivity of the mixed-metal cluster [Os 6(CO) 17(Au 2dppm)] towards gold electrophiles (dppm=Ph 2PCH 2PPh 2)

Reduction of the mixed-metal octanuclear cluster [Os 6(CO) 17(Au 2dppm)] ( 1) with Na–Hg amalgam and subsequent reaction with one equivalent of [Au 2dppm][NO 3] affords two isomers of the neutral decanuclear cluster [Os 6(CO) 17(Au 2dppm) 2] ( 2a, 2b). In a similar reaction between the reduced form of 1 with two equivalents of [AuPPh 3][NO 3] gives two isomers of the related cluster [Os 6(CO) 17(Au 2dppm 2)(AuPPh 3) 2] ( 3a, 3b). All the new clusters have been characterised by IR and NMR spectroscopy and FAB mass spectrometry. The molecular and crystal structure of 2a has been established by a single-crystal X-ray structure. In 2a the six Os atoms define an octahedron, in contrast to the bicapped tetrahedral osmium core previously observed for 1. Two of the Au atoms in 2a cap adjacent triangular faces of the Os 6 octahedron while the third spans an open OsAu 2 triangle, and the fourth caps a closed OsAu 2 triangle. Overall the decametal core may be viewed as an octahedron fused with a capped square based pyramid.

ChemInform Abstract: Compelled Orientational Control of the Solid-State Photodimerization of trans-Cinnamamides: Dicarboxylic Acid as a Non-covalent Linker.

Abstract The 2:1 hydrogen-bonded cocrystals 1a·ox, 1a·su, 1a·pht, 1a·fu, 1b·ox, 1c·ox, 1d·ox between trans-cinnamamides (1a–1d) and dicarboxylic acids (ox, su, gl, fu, pht) were prepared and characterized by IR and powder X-ray techniques. The crystal structures of 1a·pht, 1a·ox and 1a·fu were solved by single crystal X-ray diffraction. Phthalic acid (pht) caused β-type photodimerization of trans-cinnamamide (1a) in the cocrystal and functioned as a non-covalent linker like gauche 1,2-diamines in photodimerization of trans-cinnamic acids. Oxalic acid (ox) enforced 1a to take a bilayer structure that is suitable for β-type photodimerization. In the case of fumaric acid (fu), cross photodimerization with 1a occurred to give a cycloadduct 4. For the cocrystals 1a·pht and 1a·fu, pedal-like motion was assumed to occur prior to the dimerization.

The photolysis of Fe(CO) 3{P(OPh) 3} 2 and reaction of the photoproduct with alkynes: crystal structures of Fe(CO) 2{P(OPh) 3} 2(η 2-PhCCPh), Fe(CO) 2{P(OPh) 3} 2{η 1:η 1-C(O)C(Me)C[CH(OEt) 2]C(O)} and Fe 2(CO) 4{P(OPh) 3} 2(PhCCH) 2

UV-irradiation of Fe(CO) 3{P(OPh) 3} 2 ( 1) afforded an orthometallated iron hydride HFe(CO) 2{P(OPh) 3}{(PhO) 2POC 6H 4} ( 2) which was reacted in situ with alkynes R 1CCR 2. Internal alkynes reacted to give either η 2-alkyne Fe(CO) 2{P(OPh) 3} 2(η 2-R 1CCR 2) [ 3a, R 1=R 2=Ph; 3b, R 1=Ph, R 2=CH(OEt) 2] or maleoyl Fe(CO) 2{P(OPh) 3} 2{η 1:η 1-C(O)C(R 1)C(R 2)C(O)} [ 4a, R 1=Ph, R 2=Me; 4b, R 1=R 2=Me; 4c, R 1=Me, R 2=CH(OEt) 2; 4d, R 1=Me, R 2=CH 2OH; 4e, R 1=R 2=CH 2OH] complexes. The terminal alkyne HCCPh reacted with 2 to give the ferrole derivative Fe 2(CO) 4{P(OPh) 3} 2(PhCCH) 2 ( 5). The crystal structures of 3a, 4c and 5 were determined. Complex 3a is trigonal bipyramidal about the iron atom with trans apical phosphite ligands and an equatorial arrangement of the CO groups and alkyne CC moiety. Complex 4c is octahedral with trans phosphite ligands and cis carbonyl groups. The alkyne ligand has undergone double carbonylation to generate a ferracyclopentenedione (maleoyl) ring that occupies the remaining two coordination sites at the metal centre. Complex 5 is formally a derivative of Fe 2(CO) 9 in which an Fe(CO) 2{P(OPh) 3} moiety is π-bonded to a ferracyclopentadiene ring arising from the tail-to-tail coupling of two HCCPh ligands.

Compelled Orientational Control of the Solid-State Photodimerization of trans-Cinnamamides: Dicarboxylic Acid as a Non-covalent Linker

The 2:1 hydrogen-bonded cocrystals 1a·ox, 1a·su, 1a·pht, 1a·fu, 1b·ox, 1c·ox, 1d·ox between trans-cinnamamides (1a–1d) and dicarboxylic acids (ox, su, gl, fu, pht) were prepared and characterized by IR and powder X-ray techniques. The crystal structures of 1a·pht, 1a·ox and 1a·fu were solved by single crystal X-ray diffraction. Phthalic acid (pht) caused β-type photodimerization of trans-cinnamamide (1a) in the cocrystal and functioned as a non-covalent linker like gauche 1,2-diamines in photodimerization of trans-cinnamic acids. Oxalic acid (ox) enforced 1a to take a bilayer structure that is suitable for β-type photodimerization. In the case of fumaric acid (fu), cross photodimerization with 1a occurred to give a cycloadduct 4. For the cocrystals 1a·pht and 1a·fu, pedal-like motion was assumed to occur prior to the dimerization.

Addition of OH- and Alcohols or Amines to −C⋮N and −CHCH2 Groups of CH2CHCN Coordinated to Cp*Ir(η3-CH2CHCHPh)

Hydroxide ion and alcohols or amines are added regioselectively to the −C⋮N and −CHCH2 groups of CH2CHCN in [Cp*Ir(η3-CH2CHCHPh)(NCCHCH2)]+ (1a). The unsaturated amido complex Cp*Ir(η3-CH2CHCHPh)(NHCOCHCH2) (2a), alkoxo amido complexes Cp*Ir(η3-CH2CHCHPh)(NHCOCH2CH2OR) (4, R = Me (a), Et (b)), amino amido complexes Cp*Ir(η3-CH2CHCHPh)(NHCOCH2CH2NR2) (6, R2 = Me2 (a), (Me)(H) (b)), and an amino imino−ether complex [Cp*Ir(η3-CH2CHCHPh)(NHC(OMe)CH2CH2NMe2)]+ (8) have been prepared from the reactions of 1a with OH-, OH-/ROH (R = Me, Et), OH-/HNR2 (R2 = Me2, (Me)(H)), and MeOH/NHMe2, respectively. Reactions of 2, 4, 6, and 8 with aqueous HCl yield Cp*IrCl(η3-CH2CHCHPh) and quantitative amounts of H2NCOCHCH2, H2NCOCH2CH2OR, H2NCOCH2CH2NR2, and MeOCOCH2CH2NMe2, respectively. Crystal structures of 1a and 4a have been determined by X-ray diffraction data analysis.

Synthesis and Structure of Cyclotrigermenium Salts of Tetrakis{3,5‐bis(trifluoromethyl)phenyl}borate, Tetrakis(pentafluorophenyl)borate and Tetrakis{4‐[tert‐butyl(dimethyl)silyl]‐2,3,5,6‐tetrafluorophenyl}borate: A Stable Free Germyl Cation in the Condensed Phase

The reaction of tetrakis(tri-tert-butylsilyl)cyclotrigermene (1a) with Ph3C+[3,5-(CF3)2C6H3]4B− (TFPB−), Ph3C+(C6F5)4B− (TPFPB−), and Ph3C+[4-(tBuMe2Si)C6F4]4B− (TSFPB−) in benzene produced the stable free tris(tri-tert-butylsilyl)cyclotrigermenium ion (2a+) with the corresponding tetraarylborate as the counterion. The crystal structures of 2a+TFPB− and 2a+TSFPB− reveal a free germyl cation with a two π-electron system. The three-membered ring of germanium atoms constitutes an almost equilateral triangle. The cyclotrigermenium tetraarylborates, 2a+TFPB−, 2a+TPFPB−, and 2a+TSFPB−, are stable in solution. The spectroscopic data show that 2a+ is a free germyl cation, does not coordinate to either the solvent molecules (dichloromethane, chloroform, toluene, or diethyl ether) or the counter anions (TFPB−, TPFPB−, or TSFPB−). The tris(tri-tert-butylgermyl)cyclotrigermenium ion (2b+) was also characterized.

New Tetrathiafulvalene-π-Spacer-Acceptor Derivatives: Synthesis, Crystal Structure, Optical and Electrochemical Properties

4-[2-tetrathiafulvalenyl-ethenyl]pyridine (1) has been prepared from a Wittig reaction between formyltetrathiafulvalene and 4-picolyltriphenylphosphonium chloride hydrochloride. Conversion of the pyridine moiety of 1 by reaction with methyl iodide leads to 4-[2-tetrathiafulvalenyl-ethenyl]-1-methylpyridinium iodide (2a). Neutralization of 1 with a large excess of L-tartaric acid affords 4-[2-tetrathiafulvalenyl-ethenyl]-1-methylpyridinium hydrogen tartrate (3). These TTF-π-spacer-acceptor compounds have been characterized by elemental analysis, and IR and 1H NMR spectroscopy. The crystal structure of 2a has been determined by X-ray diffraction. The cation is essentially planar. Examination of the bond lengths in 2a, UV/Vis spectra and CV data, and calculations indicate that an intramolecular charge transfer occurs in the studied compounds, although it is rather limited, and larger in 2a and 3 than in 1.

Activation of Acetonitrile in [Cp*Ir(η3-CH2CHCHPh)(NCMe)]+: Crystal Structures of Iridium−Amidine, Imino−Ether, Amido, and Amide Complexes

Reactions of [Cp*Ir(η3-CH2CHCHPh)(NCMe)]OTf (1) with protic amines, alcohols, and water produce amidine complexes [Cp*Ir(η3-CH2CHCHPh)(NHC(NR2)Me)]OTf (2) (R2 = (Me)2 (a), (Me)(H) (b), (i-Pr)(H) (c), (−CH2(CH2)3CH2−) (d)), imino−ether complexes [Cp*Ir(η3-CH2CHCHPh)(NHC(OR‘)Me)]OTf (4) (R‘ = Me (a), Et (b), i-Pr (c)), and amido complex Cp*Ir(η3-CH2CHCHPh)(NHC(O)Me) (5-K), respectively. The keto form amido complex 5-K undergoes tautomerization to give the enol form complex Cp*Ir(η3-CH2CHCHPh)(NC(OH)Me) (5-E) in polar solvents. Tertiary amines (NMe3, NEt3) react with 1 in chlorinated solvents (XCl) to give the chloro complex Cp*IrCl(η3-CH2CHCHPh) (3) and quaternary ammonium salts [R3NX]OTf (R = Me, Et and X = CH2Cl, CH3, CHCl2, CCl3, PhCH2). Crystal structures of 2a, 4a, 5-K, and [Cp*Ir(NHC(OH)Me)(OH2)(PPh3)]OTf2 (6) have been determined by single-crystal X-ray diffraction analysis, which lead us to suggest hybrid structures, Ir−-NH−C(N+Me2)Me (2a‘) for 2a and Ir−-NH−C(O+Me)Me (4a‘) for 4a to some extent. Co...