Crystal structures butadienes

Chromium, (ri6-benzene)tricarbonyl-stereochemistry nomenclature, 1,131 Chromium complexes, 3,699-948 acetylacetone complex formation, 2,386 exchange reactions, 2,380 amidines, 2,276 bridging ligands, 2,198 chelating ligands, 2,203 anionic oxo halides, 3,944 applications, 6,1014 azo dyes, 6,41 biological effects, 3,947 carbamic acid, 2,450 paddlewheel structure, 2, 451 carboxylic acids, 2,438 trinuclear, 2, 441 carcinogenicity, 3, 947 corroles, 2, 874 crystal structures, 3, 702 cyanides, 3, 703 1,4-diaza-1,3-butadiene, 2,209 1,3-diketones... 

From their crystal structures, (l,3-diene)CrL4 complexes46 are found to be approximately octahedral coordinate. The low temperature (—90 °C) 13C NMR spectrum of (butadiene)Cr(CO)4, which consists of 3 M-CO signals (1 2 1 ratio), is consistent with this static structure. At higher temperature, these coalesce into a single signal20. The chiral complex (2-ethyl-l,3-butadiene)Cr(CO)4 (8) shows similar behavior, however... 

Reaction of (butadiene)ZrCp2 (31/32), and substituted Cp variants, with a wide range of metal-carbonyl complexes, generates the chelated metal-carbene complexes 163 (equation 22)163. The crystal structure of a number of these complexes has been determined... 

Later, Tieke reported the UV- and y-irradiation polymerization of butadiene derivatives crystallized in perovskite-type layer structures [21,22]. He reported the solid-state polymerization of butadienes containing aminomethyl groups as pendant substituents that form layered perovskite halide salts to yield erythro-diisotactic 1,4-trans polymers. Interestingly, Tieke and his coworker determined the crystal structure of the polymerized compounds of some derivatives by X-ray diffraction [23,24]. From comparative X-ray studies of monomeric and polymeric crystals, a contraction of the lattice constant parallel to the polymer chain direction by approximately 8% is evident. Both the carboxylic acid and aminomethyl substituent groups are in an isotactic arrangement, resulting in diisotactic polymer chains. He also referred to the y-radiation polymerization of molecular crystals of the sorbic acid derivatives with a long alkyl chain as the N-substituent [25]. More recently, Schlitter and Beck reported the solid-state polymerization of lithium sorbate [26]. However, the details of topochemical polymerization of 1,3-diene monomers were not revealed until very recently. 

The X-ray crystal structure of the 1 -tosyl-1H-1,2-diazepine (10) shows a boat conformation with N(l) at the prow (Figure 1) (72T581). Double bonds are clearly localized at N(2)—C(3) 1.255 A, C(4)—C(5) 1.326 A, and C(6)—C(7) 1.333 A, and the imine bond is isolated, whereas bond delocalization is present in the butadiene-like part C(4)—C(5)—C(6)—C(7). In contrast, when the diazepine is complexed with Fe(CO)3, for example (11), the iron atom is bound to the butadiene moiety C(4) to C(7), as also occurs in the lf/-azepine and l-methoxycarbonyl-l//-azepine complexes the N(l) atom adopts a planar sp2 configuration and the seven-membered ring consists of the two planar parts bent along the C(4)... C(7) line by 140° (70AG(E)958). 

The crystal structures of 1-(4-methyl-l-pyrazolin-3-yl)-5,5-bis(trifluo-romethyl)-AM,2,3-triazoline, the 2 1 cycloadduct of diazomethane and 4-methyl-l,l-bis(trifluoromethyl)-2-aza-l,3-butadiene,359 387 1,4-... 

Similarly, the crystal structures of [4+2] cycloadducts from electronically stabilized thiones with either butadienes 42 <1998EJ02861> or benzynes 43 (Scheme 4) <2000BCJ155> have been determined to confirm the regiochem-ical assignments derived from NMR spectroscopy. 

Tertiary phosphines have been found only in equatorial sites, as in the crystal structures of Os3(CO)uL where L = P(OMe)3 (331) or P Bu2NH2 (174). Isomers are possible within this constraint (21,318). Reactions of Os3(CO)10(MeCN)2 or the 1,1- and 1,2-butadiene compounds with PMe2Ph give two separable isomers 1,1- and l,2-Os3(CO)10(PMe2Ph)2. Variable temperature 31P-, 13C- and H-nmr spectra show that there are two rapidly interconverting 1,2-isomers. On the basis of these data, the isomers 53,54, and... 

For dienes such as norbornadiene and butadiene, a 1 1 adduct with the Ni(S2C2R2)2 (R = Ph, CF3) is formed. The adduct was originally proposed to have the structure of (12) (62). Subsequent study showed that only 13 is formed (2,3-dimethylbutadiene is used to illustrate the structures) (69, 71). Crystal structure of the adduct between 1,3-cyclohexadiene and Pd(sdt)2 was unambiguously established in later work by Clark et al. (73) (14). The olefin binds to the sulfur atoms across the ligands. 

The reaction of butadiene iron tricarbonyl, Fe(CO)3(C4H6), in liquid SO2 with BF3 leads to an interesting product containing an O-bonded RSO2 moiety A crystal structure analysis (Fig. 34) of the product showed the presence of allylic and O-sulfinate interactions with Fe, resulting from electrophilic attack of SO2 on the coordinated butadiene group. In addition, a BF3 group was found to be bound reversibly to the... 

The all-c/s-stereochemistry of the annulation product 9a was unambiguously confirmed by X-ray crystal structure analysis [9]. Subsequently, the reactions of the 4-silyloxy-l-benzothiopyrylium-salt la with a number of 4-substituted-2-silyloxy-l,3-butadienes and 3,4-disubstituted-2-silyloxy-l,3-butadienes (Table 1) were studied. In each case only one out of 4 diastereomers was isolated, namely the all-cis-stereoisomer. Yields are ranging from 68 to 91 %. 

CpLuCl2(THF)2 reacts with 2 equiv. of Na[PhCH= CHPh] in DME with dimerization of the stilbene radical anions to form [Na(DME)3][Cp2Lu /u.-CH(Ph)CH(Ph)-CH(Ph)CH(Ph) ] containing a dianionic 1,2,3,4-tetraphenyl-butadiene ligand. X-ray crystal structure determination shows Lu coordinated to two Cp rings and the dianionic butadiene ligand in an rj and 1,4-diyl fashion. ... 

The crystal structure analysis (64) of the vitamin A aldehyde complex (75) (R = CHO), which confirms that suggested (63) on the basis of the NMR spectrum, shows a bonding of the Fe(CO)3 to the polyene chain quite analogous to that observed in several butadiene-(or substituted butadiene-)metal complexes (59, 113). The iron-carbon atom distances and the carbon-carbon bond lengths, clearly suggest (64) a CT,7r-bonded rather than a two-rr-bonded structure. A similar a,Tr bonding has been proposed for the complexes l,l -bicyclopentenyl, -hexenyl, and -heptenyltricarbonyliron (76) (391), and for the tricarbonyliron complex... 

When butadiene is treated with RuCls in 2-methoxyethanol at 100°C, yellow-brown crystals of composition (C4H8)3RuCl2 are obtained 381). Crystal structural analysis has identified 381, 382] the complex as (2,6,10-dodecatriene-l,12-diyl)dichlororuthenium (146), analogous to the nickel complex (194) suggested 608) as the catalytic intermediate in the nickel-catalyzed cyclic trimerization of butadiene. In this complex, the ruthenium atom has a trigonal-bipyramidal configuration with the... 

---