Search

The syntheses of the novel silicon-bridged tris(tetraorganotin) compounds MeSi(CH2SnPh2R)3 (2, R=Ph; 5, R=Me3SiCH2) and their halogen-substituted derivatives MeSi(CH2SnPh(3���n)In)3 (3, n=1; 4, n=2) and MeSi(CH2SnI2R)3 (6, R=Me3SiCH2) are reported. The reaction of compound 4 with di-t-butyltin oxide (t-Bu2SnO)3 gives the oktokaideka-nuclear (18-nuclear) molecular diorganotin oxide [MeSi(CH2SnPhO)3]6 (7) while the reaction of 6 with sodium hydroxide, NaOH, provides the trikonta-nuclear (30-nuclear) molecular diorganotin oxide [MeSi(CH2SnRO)3]10 (8, R=Me3SiCH2). Both 7 and 8 show belt-like ladder-type macrocyclic structures and are by far the biggest molecular diorganotin oxides reported to date. The compounds have been characterized by elemental analyses, electrospray mass spectrometry (ESI-MS), NMR spectroscopy, 1H DOSY NMR spectroscopy (7), IR spectroscopy (7, 8), and single-crystal X-ray diffraction analysis (2, 7, 8)., Angewandte Chemie International Edition;Vol. 59. 2020, Issue 52, pp 23892-23898

The ferrocene derivative (η5 -Cp)Fe{η5 -C5 H3 -1-(ArNCH)-2-(CH2 NMe2 )} (1; Ar=2,6-iPr2 C6 H3 )) reacts diastereoselectively with LiR by carbolithiation and subsequent hydrolysis to give (η5 -Cp)Fe{η5 -C5 H3 -1-(ArHNCHR)-2-(CH2 NMe2 )} (3: R=tBu; 4: R=Ph; 5: R=Me) in high yields. For R=tBu, the organolithium derivative (η5 -Cp)Fe{η5 -C5 H3 -1-(ArLiNCHR)-2-(CH2 NMe2 )} (2) was isolated. Compound 2 reacts with GeCl2 ⋅dioxane and SnCl2 to give the metallylene amide chlorides (η5 -Cp)Fe{η5 -C5 H3 -1-(ArMNCHtBu)-2-(CH2 NMe2 )} 6 (M=GeCl) and 7 (M=SnCl), respectively, which each contain three stereogenic centers. The potential of 7 as a ligand in transition-metal chemistry is demonstrated by formation of its complex (η5 -Cp)Fe{η5 -C5 H3 -1-(ArMNCHtBu)-2-(CH2 NMe2 )} [9, M= Sn(Cl)W(CO)5 ]. Treatment of 3 with tert-butyllithium at room temperature causes an unprecedented carbon-carbon bond cleavage whereas under kinetic control, lithiation at the Cp-3 position takes place, which leads to the isolation of (η5 -Cp)Fe{η5 -C5 H3 -1-(ArHNCHtBu)-2-(CH2 NMe2 )-3-SiMe3 } (10).

Syntheses and molecular structures of the dimeric tin-platinum complex [LSnPtCl2 (SMe2 )]2 (2), the tin-platinum clusters [{LSnPtCl(SMe2 )}2 SnCl2 )] (3) and [(LSn)3 (PtCl2 )(PtClSnCl)(LSnOHCl)] (6) (L=MeN(CH2 CMe2 O- )2 ), and of the unprecedented tin(II) aminoalkoxide-tin oxide chloride complex [O(SnCl)2 ⋅(SnL)2 ] (5) are reported. The compounds were characterized by NMR spectroscopy (1 H, 13 C, 119 Sn, 195 Pt), 119 Sn Mossbauer spectroscopy (1-3, 6), electrospray ionization mass spectrometry, elemental analyses, and single-crystal X-ray diffraction analyses (2⋅CH2 Cl2 , 3⋅2 C4 H8 O, 5, 6⋅3CH2 Cl2 ). The tin(II) aminoalkoxide [MeN(CH2 CMe2 O)2 Sn]2 (1) behaves like a neutral ligand, inserts into a Pt-Cl bond, or is involved in rearrangement reactions with the different behavior occurring even within one compound (3, 6). DFT calculations show that the tin-platinum compounds behave like electronic chameleons.

Herein, we report the syntheses of the novel P(O)(Oi-Pr)2- and organostannyl-substituted ferrocene derivatives Fe[{η5-C5H3-1-SnPh3-2-P(O)(Oi-Pr)2}{η5-C5H4P(O)(Oi-Pr)2}] (1a), Fe[η5-C5H3-1-SnPh3-2-P(O)(O-i-Pr)2]2 (1b), Fe[{η5-C5H2-1,3-(SnPh2X)2-2-P(O)(Oi-Pr)2}{η5-C5H4P(O)(Oi-Pr)2}] (2, X = I; 3, X = Br; 4, X = Cl; 5, X = F) and η5-CpFeη5-C5H-1,3-(SnPh3)2-4,5-[P(O)(Oi-Pr)2]2 (7). Furthermore, we report the synthesis of the organotin iodide η5-CpFeη5-C5H-1,3-(SnPh2I)2-4,5-[P(O)(Oi-Pr)2]2 (8), and its reactions with KF, AgPF6, I2 and AgClO4 providing the corresponding organotin derivatives η5-CpFeη5-C5H-1,3-(SnPh2I)2-4,5-[P(O)(Oi-Pr)2]2 (9), η5-CpFeη5-C5H-1,3-(SnPhI2)2-4,5-[P(O)(Oi-Pr)2]2 (10), and [η5-CpFeη5-(C5H-1-SnPh2OH-3-SnPh2-4,5-{P(O)(Oi-Pr)2}2)]ClO4∙H2O (11). The latter compound is the first example of an air stable, tetra-substituted ferrocene derivative containing a bicentric (bis)organotin cation. The compounds are characterized by elemental analyses, 1H, 13C, 31P, 119Sn NMR and IR spectroscopy, electrospray ionization mass spectrometry, and, except for 6 and 9, single crystal X-ray diffraction analyses.

The metallation of 1,3-diiodoferrocene (A) provides novel ferrocene-based D,C,D-containing (D = O, S) pincer type ligands η5-CpFeη5-C5H3-1,3-[P(D)R2]2 (1; D = O, R= OiPr, 2; D = O, R = OPh, 3; D = S, R = Ph). The corresponding organotin derivatives η5-CpFeη5-C5H2-1-SnPh3-2,5-[P(O)(O-i-Pr)2]2 (4), η5-CpFeη5-C5H2-1-SnPh2I-2,5-[P(O)(O-i-Pr)2]2 (5) and η5-CpFeη5-C5H2-1-SnMe3-2,4-[P(S)Ph2]2 (6) are reported as well. The compounds are characterized by elemental analyses, 1H, 13C, 31P, 119Sn NMR and IR spectroscopy, electrospray ionization mass spectrometry, and single crystal X-ray diffraction analyses (3 and 4).

Herein, we report the syntheses of silicon- and tin-containing open-chain and eight-membered-ring compounds Me2 Si(CH2 SnMe2 X)2 (2, X=Me; 3, X=Cl; 4, X=F), CH2 (SnMe2 CH2 I)2 (7), CH2 (SnMe2 CH2 Cl)2 (8), cyclo-Me2 Sn(CH2 SnMe2 CH2 )2 SiMe2 (6), cyclo-(Me2 SnCH2 )4 (9), cyclo-Me(2-n) Xn Sn(CH2 SiMe2 CH2 )2 SnXn Me(2-n) (5, n=0; 10, n=1, X=Cl; 11, n=1, X=F; 12, n=2, X=Cl), and the chloride and fluoride complexes NEt4 [cyclo- Me(Cl)Sn(CH2 SiMe2 CH2 )2 Sn(Cl)Me⋅F] (13), PPh4 [cyclo-Me(Cl)Sn(CH2 SiMe2 CH2 )2 Sn(Cl)Me⋅Cl] (14), NEt4 [cyclo-Me(F)Sn(CH2 SiMe2 CH2 )2 Sn(F)Me⋅F] (15), [NEt4 ]2 [cyclo-Cl2 Sn(CH2 SiMe2 CH2 )2 SnCl2 ⋅2 Cl] (16), M[Me2 Si(CH2 Sn(Cl)Me2 )2 ⋅Cl] (17 a, M=PPh4 ; 17 b, M=NEt4 ), NEt4 [Me2 Si(CH2 Sn(Cl)Me2 )2 ⋅F] (18), NEt4 [Me2 Si(CH2 Sn(F)Me2 )2 ⋅F] (19), and PPh4 [Me2 Si(CH2 Sn(Cl)Me2 )2 ⋅Br] (20). The compounds were characterised by electrospray mass-spectrometric, IR and (1) H, (13) C, (19) F, (29) Si, and (119) Sn NMR spectroscopic analysis, and, except for 15 and 18, single-crystal X-ray diffraction studies.

The novel phosphonyl-substituted ferrocene derivatives [Fe(η(5) -Cp)(η(5) -C5 H3 {P(O)(O-iPr)2 }2 -1,2)] (Fc(1,2) ) and [Fe{η(5) -C5 H4 P(O)(O-iPr)2 }2 ] (Fc(1,1') ) react with SnCl2 , SnCl4 , and SnPh2 Cl2 , giving the corresponding complexes [(Fc(1,2) )2 SnCl][SnCl3 ] (1), [{(Fc(1,1') )SnCl2 }n ] (2), [(Fc(1,1') )SnCl4 ] (3), [{(Fc(1,1') )SnPh2 Cl2 }n ] (4), and [(Fc(1,2) )SnCl4 ] (5), respectively. The compounds are characterized by elemental analyses, (1) H, (13) C, (31) P, (119) Sn NMR and IR spectroscopy, (31) P and (119) Sn CP-MAS NMR spectroscopy, cyclovoltammetry, electrospray ionization mass spectrometry, and single-crystal as well as powder X-ray diffraction analyses. The experimental work is accompanied by DFT calculations, which help to shed light on the origin for the different reaction behavior of Fc(1,1') and Fc(1,2) towards tin(II) chloride.

The reactions of boron trifluoride with the organostannylene RSnCl {R = 4-tBu-2,6-[P(O)(OiPr)2]2C6H2} and the organosilane RSiMe3 provided the corresponding 1:1 and 1:2 complexes, respectively, through the formation of P=OB interactions. In the former reaction, even with excess BF3·OEt2, no SnB complexation involving the lone electron pair at the tin(II) center was observed. The experimental results are supported by DFT calculations.

A novel synthetic route based on [4+2] cycloaddition for dibromobenzobarrelene derivatives starting from in situ generated 3,5-dibromo-1,2-didehydrobenzene and mesitylene, 1,2,4,5-tetramethylbenzene, 1,2,3,5-tetramethylbenzene, pentamethylbenzene, 1,3-dimethoxybenzene, and 2,4,6-trimethylbromobenzene, respectively, was developed. Thus, six novel dibromobenzobarrelenes with diverse substitution patterns at the barrelene framework including chiral derivatives are reported. The benzobarrelene 6,8-dibromo-1,3,10-trimethyl-1,4-dihydro-1,4-ethenonaphthalene (1a) was functionalized at the annulated benzene ring to give three novel carboxylic acids and two novel phosphonic acid esters. Selected benzobarrelene complexes with RhICl were tested for their catalytic activity in the 1,4-addition of phenylboronic acid towards cyclohex-2-enone. Turnover frequencies up to 3405 h–1 were observed, which are among the highest reported so far for Rh–diene complexes in this type of C–C coupling reaction.

The synthesis of the intramolecularly coordinated stannylenes and their transition-metal complexes of the type RN(CH2CMe2O)2SnL [1: L = lone pair, R = Me; 2: L = lone pair, R = n-octyl; 5: L =W(CO)5, R = Me; 6: L = Cr(CO)5, R = Me; 7: L =W(CO)5, R = n-octyl; 8: L = Fe(CO)4, R = Me], and of the tin(IV) compounds RN(CH2CMe2O)2SnBr2 (9: R = Me), [MeN(CH2CMe2O)2SnBr2]2·SnBr2(OH)2 (10) and spiro-[RN(CH2CMe2O)2]2Sn (3: R = Me; 4: R = n-octyl) is reported. The compounds were characterized by elemental analyses, 1H, 13C, 119Sn, and 119Sn magic-angle spinning (5, 6) NMR spectroscopy, electrospray mass spectrometry, and single-crystal X-ray diffraction analysis.

Das zunehmende Interesse an der Chemie von Organozinnchalkogeniden ist das Resultat ihrer fesselnden chemischen und physikalischen Eigenschaften und den damit verbundenen potenziellen technischen Anwendungen, z.B. als Halbleiter oder in der nichtlinearen Optik. Es sind einige dimere und trimere Triund Diorganozinnchalkogeniden bekannt, in denen die Chalkogenatome die verbr ckenden Positionen besetzen. Ferner gibt es wenige Beispiele von Organozinnchalkogeniden, die terminale Sn=E-Bindungen enthalten (E= S, Se, Te). In den letzten Jahren haben Monoorganozinnchalkogenide besondere Aufmerksamkeit erfahren. Besonders popul r sind dabei Zinnsesquichalkogenide der allgemeinen Formel [(RSn)4E6]. Sie weisen eine K figstruktur auf und enthalten sowohl nichtreaktive (R=Alkyl, Aryl, CF3, C6F5) als auch funktionalisierte organische Substituenten (R= CH2CH2COOH, CH(CH2COOH)2). [3] Diese Verbindungen liegen als Adamantanoder Doppeldecker-Strukturen vor (Schema S1). Dehnen und Mitarbeiter haben gezeigt, dass anionogene Zinnchalkogenidpolymere [(RSn)2E3 2 ]1 mit funktionalisierten organischen Substituenten ebenfalls zug nglich sind. Monoorganoelementchalkogenide der Elemente der 14. Gruppe der allgemeinen Formel R2M2E3 (R= organische Gruppe; E= S, Se, Te) zeigen [1.1.1]PropellanStruktur, was sowohl durch theoretische Rechnungen vorausgesagt als auch experimentell bewiesen wurde (Schema S1). K rzlich wurde auch ber Verbindungen der Zusammensetzung R2Sn2Te5 mit sterisch anspruchsvollen Arylsubstituenten berichtet. Alle diese Verbindungen enthalten jedoch einfach gebundene Chalkogenatome in den verbr ckenden Positionen, und die meisten Untersuchungen sind auf Sulfide und Selenide beschr nkt (Schema S1). Die entsprechenden Tellurverbindungen wurden bisher nicht detailliert untersucht. Sie sind gewchnlich thermisch instabil und empfindlich gegen Licht. K rzlich haben wir ber die Organozinn(I)-Verbindung [2,6-(Me2NCH2)2C6H3Sn]2 (1) berichtet und gezeigt, dass die Verwendung von intramolekular koordinierenden Zangenliganden ein alternatives Konzept zum Einsatz von sterisch anspruchsvollen Substituenten f r die Stabilisierung von reaktiven Distanninderivaten darstellt. Die Oxidation von 1 mit elementarem Schwefel oder Selen lieferte die neuartigen Monoorganozinnchalkogenide [2,6(Me2NCH2)2C6H3Sn]2E, [2,6-(Me2NCH2)2C6H3Sn(Se)]2Se bzw. [{2,6-(Me2NCH2)2C6H3}2Sn2S7]. [9] Im Rahmen systematischer Studien zur Reaktivit t des Distannins 1 berichten wir hier ber seine Reaktion mit elementarem Tellur unter schrittweiser Oxidation des Zinn(I)Atoms (Schema 1).

The syntheses of the tin compounds [LSn]2 (2), spiro-L2Sn (3), [LSnW(CO)5]2 (4), [LSnBr2]2 (5), spiro-L2Sn·SnBr4 (6) and LSn[OC(O)Ph]2 (8), where L = MeN(CH2CMe2O)[(S)-CH(Me)-(R)-CH(Ph)O], and (Ph4P)2SnBr6 (7) are reported. The compounds were characterized by elemental analysis, multinuclear NMR spectroscopy including 119Sn cross polarisation–magic angle spinning NMR (CP–MAS) (2, 3–6), electrospray ionization mass spectrometry (2–4) and single crystal X-ray diffraction analysis (2, 2·C7H8, 3a, 3b, 4·C7H8, 5, 6·C7H8, 7).

Both the racemic and the stereoselective synthesis of the silicon-modified amino acid p-(tBu2FSi)C6H4CH2(NH2)COOH (SiFA-phenylalanine, 6) and its derivatives p-(tBu2FSi)C6H4CH2(NHBoc)COOH (10) and p-(tBu2FSi)C6H4CH2(NHFmoc)COOH (11) are reported. The latter two compounds are valuable building blocks for the convenient introduction of silicon-based fluoride acceptors (SiFAs) into peptides by solid-phase peptide syntheses (SPPS). As prove of principle, the Tyr3-octreotate derivatives 12, 13 and 14 were prepared by using standard protocols of the solid-phase peptide synthesis (SPPS). They were labelled with 18F-fluorine by isotopic exchange in radiochemical yields of up to 70 % (with radiochemical purity ranging between 92 and 99 %). The incorporation of 18F-fluorine into the SiFA-modified amino acid 6 was studied as the latter may also serve as a tracer in PET. After purification, [18F]-6 showed a remarkable stability in an isotonic solution. Also reported is the molecular structure, as determined by single-crystal X-ray diffraction analysis, of p-(tBu2FSi)C6H4CHCH[C(O)OMe]NHC(O)OCH2Ph (8), which serves as a precursor for the stereoselective synthesis of compound 6.

The synthesis of the intramolecularly coordinated pentacarbonyltungsten–organostannylene complexes {2,6-(Me2NCH2)2C6H3}Sn(H)W(CO)5 (2) and [{2,6-(Me2NCH2)2C6H3}Sn(μ-OH)W(CO)5]2 (3) and the solid-state molecular structure of 3, as determined by single-crystal X-ray diffraction analysis, are reported. Compound 3 is characterized by hydroxido bridges [Sn–O 2.068(5), 2.231(5) A], an intramolecular NSn coordination bond [2.501(7) A] and an intramolecular O–H···N hydrogen bond [O···N 2.715(8) A].

The compound 5-chloro-1-aza-5-silatricyclo[3.3.3.01,5]undecane (C9H18NSiCl) combines with water to form an association complex with the formula C9H18NSiCl·H2O. Proton NMR studies at various temperatures, concentrations and magnetic fields indicate that this compound exists in solution as an equilibrium mixture of the initial chloride and its association complex with water, a structure for which is proposed. Evidence is provided against a rigid hexacoordinate complex. The equilibrium is shown to correspond to a reversible hydrolysis of C9H18NSiCl which is nucleophilically activated by the intramolecularly coordinating nitrogen present in situ. The reverse reaction is the decomposition of the association complex C9H18NSiCl·H2O to C9H18NSiCl and free water. As a consequence, this paper presents a reversible hydrolysis of a chlorosilane interconverting two directly observable pentacoordinate species without addition of an external nucleophile, and proceeding with retention of configuration at the silicon atom. We further argue that this reaction cannot proceed through a rigid hexacoordinate octahedral intermediate, but could proceed through two non-rigid species, the averaged dynamic behaviour of which is identical to a non-octahedral hexacoordinate transition state.

The synthesis of the intramolecular penta and hexa-coordinated tin compounds [MeN(CH2CH2CH2)2SnS]2 3, and [(CH2N(Et)CH2CH2CH2)2 SnS]2 5, is described and their 1H, 13C and 119Sn NMR data are reported. 5 crystallizes in the monoclinic space group P21/C with the unit cell dimensions a =8.977(2), b = 13.053(2), c = 13.310(1) A, β = 103.54(2)ρ, V 1516.3(5) A3, ρ= 1.529 g/cm3, Z=2. The structure was refined to a final R value of 0.058 for 1.774 observed independent reflections. The tin atoms are hexa-coordinated by 2 C, 2 S and 2 N. The intramolecular Sn-N distances amount to 2.766 and 2.859 A.

The reaction of bis(halodiphenylstannyl)methanes with HMPA leads to the formation of the one-to-one complexes (Ph2XSn)2CH2. HMPA (X-Cl,Br,I). The reaction of bis-1,3(chlorodiphenylstannyl)propane with HMPA yields the one-to-two complex (Ph2ClSnCH2)2CH2. 2 HMPA, whereas from bis(dibromophenylstannyl)methanes both the one-to-one and the one-to-two complexes (PhBr2Sn)2CH2-n HMPA (n=1,2) have been isolated. The solid structure of (Ph2XSn)2CH2. HMPA (C=Cl,Br), determined by X-ray diffraction, shows for both tin atoms a distorted trigonal bipyramidal structure, one by complexation of the HMPA, the other one by intramolecular coordination of a halogen atom. Temperature dependent 1H, 13C, 31P and 119Sn NMR and IR measurements prove the intramolecular mobility of these compounds.

The reaction of silver perchlorate with [PhI 2 SnCH 2 ([16]crown-5)] (1) and [I 3 SnCH 2 ([16]crown-5)] (2) gave the organotin(IV)-substituted crown ether complexes [PhSnCH 2 ([16]crown-5)][ClO 4 ] 2 (3) and [HOSnCH 2 ([16]crown-5)][Y] 2 (4: Y= ClO 4 , 5: Y=CF3 S 03 ) , respectively. All compounds have been isolated as air-stable materials and characterised by 1 H, 13 C, 119 Sn and 119 Sn MAS (5) NMR spectroscopy, ESIMS spectrometry, elemental analysis and by single-crystal X-ray diffraction analysis. The molecular structures of 3-5 show that the tin(IV) cation fits perfectly into the crown ether cavity and is coordinated by the five oxygen atoms of the ring to give a pentagonal bipyramidal configuration about the central metal cation. Notably, compounds 4 and 5 contain the first monomeric monoorganotin dication. Moreover, there are 3 J( 1 H, 119 Sn) coupling constants to the CH 2 CH proton of 377 (3) and 470 Hz (4, 5) that are, to the best of our knowledge, the biggest such couplings ever reported.

The molecular structures of the intramolecularly coordinated tungstenpentacarbonyl organostannylene complexes 2,6-(Me 2 NCH 2 ) 2 C 6 H 3 (Cl)SnW(CO) 5 and [2,6-(Me 2 NCH 2 ) 2 C 6 H 3 -(H 2 O)SnW(CO) 5 ] + (CB 11 H 12 ) - are reported. The latter compound is an aqua complex in which the water molecule replaces one of the two N→Sn coordination sites. The coordination of the water molecule is accompanied by proton transfer to the nitrogen atom. DFT calculations reveal this to be the thermodynamically most-stable structure.

UV-irradiation of the diorganosilane [4-tBu-2,6-{P(O)(OiPr)2}2C6H2]SiH2Ph in the presence of W(CO)6 provided a mixture consisting of the diorganosilylene tungsten pentacarbonyl complex [4-tBu-2,6-{P(O)(OiPr)2}2C6H2](Ph)SiW(CO)5 (2), the organosilylium salt [4-tBu-2,6-{P(O)(OiPr)2}2C6H2Si(H)Ph]+[{(CO)5W}2H]– (3), and an unidentified species. UV-irradiation of the triorganosilane [4-tBu-2,6-{P(O)(OiPr)2}2C6H2]SiHPh2 in presence of W(CO)6 provided the organosilylium salt [4-tBu-2,6-{P(O)(OiPr)2}2C6H2SiPh2]+[{(CO)5W}2H]– (6) whereas, under the same conditions, no reaction was observed between the tetraorganosilane [4-tBu-2,6-{P(O)(OiPr)2}2C6H2]SiPh3 and W(CO)6. The reaction of compound 2 with Ph3C+PF6– gave the fluorine-substituted silylene complex [4-tBu-2,6-{P(O)(OiPr)2}2C6H2](F)SiW(CO)5 (4) whereas the reactions of 3 with Ph4PBr and 5 with water gave the benzoxasilaphospholes 3a, 3b, and 7, respectively. The compounds 2 and 6 were isolated and characterized by 1H, 13C, 29Si, 31P NMR, and IR spectroscopy, electrospray ionization mass spectrometry, and in case of 2 also by single-crystal X-ray diffraction analysis. The compounds 3, 3a, 3b, 4, and 7 were not isolated but identified unambiguously by NMR spectroscopy and electrospray ionization mass spectrometry.

The synthesis of the intramolecularly coordinated organostannylene ruthenium complex [4-tBu-2,6-{P(O)(O-iPr)2}2-C6H2]Sn(Cl)Ru(C6H6)Cl2, 1, is reported. It is characterized by elemental analysis, 1H, 13C, 31P, 119Sn NMR spectroscopy, and, as its toluene solvate 1·C7H8, by single-crystal X-ray diffraction analysis. In compound 1·C7H8 the tin atom is five-coordinate and shows a strongly distorted trigonal-bipyramidal configuration. The intramolecular O–Sn distances are 2.291(3) and 2.394(3) A. The Sn–Ru distance is 2.5856 A.

A highly efficient (18)F-labeling synthon for universal protein labeling is reported. Diverse (18)F-labeled proteins of 66-144 kDa were prepared with [(18)F]SiFA-isothiocyanate synthesized by an isotopic (19)F for (18)F exchange at the silicon atom. Overall preparative radiochemical yields were 20-40 % after 40-50 min. No bone uptake of (18)F radioactivity was detected until 90 min post-injection of (18)F-SiFA-RSA; this demonstrates the metabolic stability of the [(18)F]SiFA moiety.

Single crystal X-ray diffraction analyses of LSn(OCH2CH2)2NR [1, R = Me, L = lone pair; 2, R = Me, L = W(CO)5; 3, R = t-Bu, L = W(CO)5] reveal these compounds to be dimeric and cis-configurated. The dimerization is realized by intramolecular OSn interactions to give four-membered Sn2O2-rings. In addition, there are intramolecular NSn interactions ranging in between 2.356(5) (2) and 2.549(4) A (3).

Single-crystal X-ray diffraction analysis of [2,6-(Me2NCH2)2C6H3]2SnF2 reveals that only one of the two dimethylaminomethyl groups of each pincer-type ligands [2,6-(CH2NMe2)2C6H3]− is coordinated to the tin atom at Sn-N distances of 2.576(2) and 2.470(2) A, inducing chirality of the latter. The tin atom exhibits a distorted octahedral trans(C,C)cis(N,N)cis(F,F) configuration. Extensive intra- and intermolecular C-H···F hydrogen bonding is observed with the latter giving rise to formation of polymeric chains.

Hypervalent diorganotin(IV) dihalides of the type RBuSnX2 [R = 2-(Me2NCH2)C6H4; X = Cl (1), F (2)] and heterocyclic derivatives of the type (RR1SnS)2 [R1 = Bu (3) and 2-(Me2NCH2)C6H4 (4 and 4·2CHCl3)] have been prepared. Their behaviour in solution was investigated by multinuclear NMR spectroscopy. The molecular structures of these compounds were established by single-crystal X-ray diffraction. The strength of the intramolecular SnN coordination as a function of the substituent pattern at the tin atom is discussed. Weak intermolecular Sn···Cl interactions result in a “zig-zag” polymeric chain for dichloride 1, while difluoride 2 is a polymer with a linear –Sn–F–Sn– skeleton. In both compounds, a distorted octahedral (C,N)CSnX3 configuration is observed. The thio derivatives are monomeric and exhibit distorted trigonal bipyramidal (C,N)CSnS2 (3) or distorted octahedral (C,N)2SnS2 (4 and 4·2CHCl3) configurations. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

The synthesis of [Me2N(CH2)2]2Sn(OSit-Bu2OH)2 (1) by the base-assisted cohydrolysis of [Me2N(CH2)2]2SnCl2 and t-Bu2SiCl2 is described. The molecular structure of 1, determined by single crystal X-ray diffraction analysis, features a pentacoordinated tin atom owing to the intramolecular coordination of the nitrogen atom of one 3-dimethylaminopropyl group, and reveals both intramolecular Si(Sn)O···H-O and intermolecular N···H-O hydrogen bonding. Compound 1 is a rare example of a metallasiloxanol and holds potential for the preparation of multi component oxide materials. Synthese und Struktur des ersten Stannadisiloxandiols: [Me2N(CH2)2]2Sn(OSit-Bu2OH)2. Ein potentieller Baustein fur die Darstellung von Multikomponentenoxiden Es wird uber die Synthese von [Me2N(CH2)2]2Sn(OSit-Bu2OH)2 (1) durch basische Cohydrolyse von [Me2N(CH2)2]2SnCl2 und t-Bu2SiCl2 berichtet. Die Kristall- und Molekulstruktur von 1 wurden durch eine Einkristallrontgenstrukturanalyse bestimmt. Das Zinnatom ist infolge der intramolekularen Koordination des Stickstoffatoms einer 3-Dimethylaminopropylgruppe pentakoordiniert. Die Verbindung zeigt sowohl intramolekulare Si(Sn)O···H-O als auch intermolekulare N···H-O Wasserstoffbruckenbindungen. Verbindung 1 ist ein seltenes Beispiel eines Metallasiloxanols und von Interesse fur die Darstellung von Multikomponentenoxiden.

It is demonstrated that long-range nJ(1H,117Sn) coupling constants down to 0.3 Hz, can be accurately quantified from non-linear fitting of the sine modulation of the associated 1H117Sn correlation cross-peak intensities sampled as a function of the heteronuclear antiphase coherence preparation time in the 1H117Sn J-HMQC pulse sequence. The contribution of additional, undesired modulations is illustrated and assessed using the product operator formalism, and is traced back to contributions that arise from miss-setting of the wandering 180° pulse angle in the constant time period. The power of the method and its use in the characterization of weak intramolecular donor–acceptor interactions are illustrated by the determination of long-range nJ(1H,117Sn) coupling constants of bis[3-(dimethylamino)propyl]tin derivatives, [Me2N(CH2)3]2SnR2 (2, R = Me; 3, R = Ph; 4, R = t-Bu). By comparing these with the values found for the corresponding bis(4-methylpentyl)tin derivatives, [Me2CH(CH2)3]2SnR2 (2′, R = Me; 3′, R = Ph), which lack such interactions, the use of long-range coupling constants to detect intramolecular donor–acceptor interactions is evaluated. It is concluded that nJ(1H,117Sn) couplings up to six bonds through an organic carbon chain can be quantified, whether donor–acceptor interactions are present or not. Furthermore, evidence is presented that, when two scalar coupling pathways co-exist, the pathway involving an intramolecular donor–acceptor interaction can have opposite sign, thus decreasing the overall coupling constant to a value smaller than that actually measured in the absence of a donor–acceptor interaction, where only one coupling pathway is active. There is nevertheless clear numerical value discrimination in the series of compounds investigated between long-range couplings in derivatives without weak intramolecular donor–acceptor interactions and those where such interactions can exist. Copyright © 2004 John Wiley & Sons, Ltd.

The synthesis of bis[di-n-alkyl(fluoro)stannyl]methanes, [(R2)FSn]2CH2, (3, R = n-octyl; 4, R = n-dodecyl), is reported and their unprecedented dimeric structure in solution with pentacoordinate tin atoms is rationalized on the basis of 19F and 119Sn NMR spectroscopy, osmometric molecular mass determination and electrospray mass spectrometry (ESMS). 19F and 119Sn MAS NMR and Mossbauer spectroscopy also indicate pentacoordinate tin atoms for the solid state. The ability of compounds 3 and 4 to bind fluoride ion selectively and reversibly is evaluated through potentiometric measurements. Compared with the previously reported organotin(IV)-based fluoride ionophore [Cl(Ph2)Sn]2CH2, 3 and 4 exhibit a drastically improved lifetime, while retaining their high preference for fluoride over all other lipophilic anions evaluated. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

The trinuclear organotin−oxo cluster [Ph2P(OSntBu2)2O· tBu2Sn(OH)2][O3SCF3] (6), was prepared in good yield by the consecutive reaction of (tBu2SnO)3 with F3CSO3H and Ph2PO2H, and adopts a common tricyclic ESn3O3X2 structural motif with E = P; X = OH, similar to those found in the recently reported species [M(OSntBu2)2O·tBu2Sn(OH)2] [M = Ph2Si (1), Me2Si (2), CO (3), MesB (4)] and [Ph2Si(OSntBu2)2O·tBu2SnF2] (5) where E = Si, C, B and X = OH, F. Compound 6 was characterized by multinuclear NMR spectroscopy, IR spectroscopy, electrospray mass spectrometry and single-crystal X-ray diffraction analysis. A natural population analysis (NPA) performed on the B3LYP/LANL2DZ level of theory for the molecular structures of the isoelectronic species [Ph2Si(OSntBu2)2O·tBu2Sn(OH)2] (1) and [Ph2P(OSntBu2)2O·tBu2Sn(OH)2]+ (6a) suggests that the positive charge of the latter is partially delocalised over the phenyl rings. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

The intramolecularly coordinated heteroleptic organolead(II) compounds {4-tBu-2,6-[P(O)(OEt)2]2C6H2}PbX (2, X = Cl; 3, X = SPh) have been synthesized. Single-crystal X-ray analyses reveal that both compounds adopt polymeric chain structures by intermolecular Pb−X···Pb bridges, a structural motif previously unknown for organolead(II) derivatives. Compound 2 reacts with lithium diisopropylamide, iPr2NLi, and lithium bis(trimethylsilyl)methane, (Me3Si)2CHLi, respectively, to provide in situ the corresponding organolead(II) compounds {4-tBu-2,6-[P(O)(OEt)2]2C6H2}PbX (4, X = iPr2N; 5, X = (Me3Si)2CH], which were identified by NMR spectroscopy but could not be obtained as analytically pure substances. Attempts to isolate the intramolecularly coordinated organolead(II) hexafluorophosphate {4-tBu-2,6-[P(O)(OEt)2]2C6H2}Pb+PF6− from the reaction of 2 with TlPF6 also failed. Instead, the unprecedented salt [{5-tBu-1,3-[P(O)(OEt)2]2C6H3}4·(Pb2F)] [PF6]3·4THF (6) was obtained, in which the [(Pb−F−Pb)]3+ cation is stabilized by eight intermolecular P=O⇄Pb interactions. Compound 6 was characterized by single-crystal X-ray analysis and electrospray mass spectrometry. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

The synthesis and complete characterization by multinuclear NMR, infrared, and Mossbauer spectroscopy, by single crystal X-ray analysis, as well as by electrospray mass spectrometry of the new soluble triorganotin fluoride Me2PhSnF (1) is reported. The crystal structure of 1 reveals a rod-like polymeric structure in the solid state. Solutions of 1 in apolar solvents, such as toluene, contain mixtures of interconvertible oligomers. Ab initio MO calculations on model compounds H3SnF, [H3SnFSnH3]+, and [FH3SnFSnH3F]− indicate that the Sn−F bonds are substantially ionic in character, and suggest open-chain species, rather than cyclic species. In donor solvents, such as pyridine, 1 forms complexes with the solvent, such as Me2PhSnF·pyridine. The solid-state structure of (Me3SiCH2)3SnF (2) is reformulated as monomeric with a weak intermolecular Sn···F interaction that gives rise to a [4+1] coordination. The relative short Sn−Sn separation enables the fluorine atoms to oscillate (flip-flop) between two neighboring (Me3SiCH2)3Sn− groups, which is expressed in the X-ray experiment by a dynamic disorder. Ab initio MO calculations on a model compound, [H3SnFSnH3]+, suggest only a small energy barrier for the flip-flop motion. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2003)

The syntheses and molecular structures, as determined by single-crystal X-ray diffraction analysis, of the first intramolecularly [4+2]-coordinated tetraorganolead compound {4-t-Bu-2, 6-[P(O)(OEt)2]2C6H2}PbPh3 (2) and the triphenyllead chloride adduct of the first intramolecularly coordinated benzoxaphosphaplumbole {[1(Pb), 3(P)-Pb(Ph)2OP(O)(OEt)-5-t-Bu-7-P(O)(OEt)2]C6H2·Ph3PbCl} (3a) are reported. The reaction of 2 with [Ph3C]+ [PF6]— and p-MeC6H4SO3H, respectively, provides the triorganolead salts {4-t-Bu-2, 6-[P(O)(OEt)2]2C6H2}PbPh2+X— (4, X = PF6; 4a, X = p-MeC6H4SO3). Reaction of 2 with bromine and hydrogen chloride, respectively, gives the diorganolead dihalides {4-t-Bu-2, 6-[P(O)(OEt)2]2C6H2}PbPhX2 (5, X = Br; 6, X = Cl). Die erste [4+2]-koordinierte Tetraorganobleiverbindung: Synthese, Struktur und Umwandlung in ein Triorganobleikation, ein Benzoxaphosphaplumbol und Diorganobleidihalogenide Es wird uber die Synthesen und Einkristallrontgenstrukturanalysen der ersten intramolekular [4+2]-koordinierten Tetraorganobleiverbindung {4-t-Bu-2, 6-[P(O)(OEt)2]2C6H2}PbPh3 (2) und des Triphenylbleichlorid-Adduktes des ersten intramolekular koordinierten Benzoxaphosphaplumbols {[1(Pb), 3(P)-Pb(Ph)2OP(O)(OEt)-5-t-Bu-7-P(O)(OEt)2]C6H2·Ph3PbCl} (3a) berichtet. Die Reaktion von 2 mit [Ph3C]+ [PF6]— bzw. p-MeC6H4SO3H fuhrt zu den Triorganoblei-Salzen [{4-t-Bu-2, 6-[P(O)(OEt)2]2C6H2}PbPh2]+X— (4, X = PF6; 4a, X = p-MeC6H4SO3). Die Diorganobleidihalogenide {4-t-Bu-2, 6-[P(O)(OEt)2]2C6H2}PbPhX2 (5, X = Br; 6, X = Cl) werden durch die Reaktion von 2 mit Brom oder Chlorwasserstoff dargestellt.

The syntheses of well-defined tellurastannoxanes, mer-(Bu3SnO)3Te(OH)3 (1), and trans-(Bu3SnO)2[CH2(Ph2SnO)2]2Te (2), are reported. The compounds were characterized by 119Sn and 125Te NMR spectroscopy and compound 2 also by single crystal X-ray diffraction. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)

The reaction of the organolithium derivative {2, 6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}Li (1-Li) with [Ph3C]+[PF6]— gave the substituted biphenyl derivative 4-[(C6H5)2CH]-4′-[tert-Bu]-2′, 6′-[P(O)(OEt)2]2-1, 1′-biphenyl (5) which was characterized by 1H, 13C and 31P NMR spectroscopy and single crystal X-ray analysis. Ab initio MO-calculations reveal the intramolecular O···C distances in 5 of 2.952(4) and 2.988(5)A being shorter than the sum of the van der Waals radii of oxygen and carbon to be the result of crystal packing effects. Also reported are the synthesis and structure of the bromine-substituted derivative {2, 6-[P(O)(OEt)2]2-4-tert-Bu]C6H2}Br (9) and the structure of the protonated ligand 5-tert-Bu-1, 3-[P(O)(OEt)2]2C6H3 (1-H). The structures of 1-H, 5, and 9 are compared with those of related metal-substituted derivatives. Zur Reaktion des Zangenliganden {2, 6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}— mit [Ph3C]+[PF6]—. Neuartige Umlagerung und C-C-Bindungsknupfung Die Reaktion des Organolithiumderivats {2, 6-[P(O)(OEt)2]2-4-tert-Bu-C6H2}Li (1-Li) mit [Ph3C]+[PF6]— fuhrt zur Bildung von 4-[(C6H5)2CH]-4′-[tert-Bu]-2′, 6′-[(P(O)(OEt)2]2-1, 1′-biphenyl (5), welches 1H-, 13C- und 31P-NMR-spektroskopisch und durch eine Einkristallrontgenstrukturanalyse charakterisiert wird. Ab initio MO-Rechnungen zeigen, dass die intramolekularen O···C-Abstande in 5 von 2.952(4) and 2.988(5)A das Resultat von Kristallpackungseffekten sind. Ebenfalls berichtet wird uber die Synthese und Struktur des bromsubstituierten Derivats {2, 6-[P(O)(OEt)2]2-4-tert-BuC6H2}Br (9) und die Struktur des protonierten Liganden 5-tert-Bu-1, 3-[P(O)(OEt)2]2C6H3 (1-H). Die Strukturen von 1-H, 5, und 9 werden mit denen verwandter metallsubstituierter Derivate verglichen.

The single-crystal X-ray structure analysis of hexakis(2,4,6-triisopropylphenyl)cyclotristannoxane, cyclo-[(2,4,6-i-Pr3-C6H2)2SnO]3 (1), is reported and reveals this compound to contain an almost planar six-membered ring. Redistribution reactions of 1 with cyclo-(t-Bu2SnO)3 and t-Bu2SiCl2, respectively, failed and indicate an unusual kinetic inertness of the Sn–O bonds in 1 as compared to related molecular diorganotin oxides containing less bulkier substituents. The redistribution reaction of cyclo-(t-Bu2SnO)3 with cyclo-(t-Bu2SnS)2 leads to an equilibrium involving the trimeric diorganotin oxysulphides cyclo-t-Bu2Sn(OSnt-Bu2)2S (2 a) and cyclo-t-Bu2Sn(SSnt-Bu2)2O (2 b). Hexakis(2,4,6-triisopropylphenyl)cyclotristannoxan – Ein molekulares Diorganozinnoxid mit kinetisch stabilen Sn–O Bindungen1) Es wird die Einkristallrontgenstrukturanalyse von Hexakis(2,4,6-triisopropylphenyl)cyclotristannoxan cyclo-[(2,4,6-i-Pr3-C6H2)2SnO]3 (1) vorgestellt. Die Verbindung liegt als nahezu planarer sechsgliedriger Ring vor. Das Diorganozinnoxid 1 reagiert nicht mit cyclo-(t-Bu2SnO)3 bzw. t-Bu2SiCl2, was auf die ungewohnliche kinetische Stabilitat der Sn–O Bindungen in 1 im Vergleich zu ahnlichen molekularen Diorganozinnoxiden mit sterisch weniger anspruchsvollen Substituenten hinweist. Die Redistributionsreaktion von cyclo-(t-Bu2SnO)3 mit cyclo-(t-Bu2SnS)2 fuhrt zu einem Gleichgewicht mit den trimeren Diorganozinnoxysulphiden cyclo-t-Bu2Sn(OSnt-Bu2)2S (2 a) and cyclo-t-Bu2Sn(SSnt-Bu2)2O (2 b).