Synthesis and Structure of Mixed Distannoxane Dimers [ClR2SnOSnR2′Cl]2

Mixed distannoxane dimers [ClR2SnOSnR2′Cl]2 were synthesized by the reaction of R2SnO(R=Bu,Pr) and R2SnCl2(R=Me,Ph,Cy,Oct). The crystal structures of compound 1 and 5 show they are ladder-type dimers that contain a central planar Sn2O3 four-membered ring. Both endo-and exo-Sn atoms are five-coordinate.     

Cleavage of the Fe—Fe Bond of （Me2SiSiMe2） [η^5－C5H4Fe（CO）2]2 with Na／Hg and Molecular Structure of the Ring－Opened Complex

The reaction of the rifle cyclic complex (1) with sodium amalgam in THF resulted in the expected cleavage of the Fe-Fe bond to afford his-sodium salt ( Me2SiSiMe2 ) [η^5-C5H4Fe(CO)2]2 (4). The latter was not isolated and was used directly to react with MeI, PhCH2Cl, CH3C(O)Cl, PhC(O)Cl,Cy3SnCl (Cy= cyclohexyl) or Ph3SnCl to afford corresponding ring-opened derivatives (Me2SiSiMe2) [η^5-C5H4Fe(CO)2]2 [5, R=Me; 6, R=PhCH2; 7, R=CH3C(O); 8, R=PhC(O); 9, R = Cy3Sn or 10, R = Ph3Sn ]. The crystal and molecular structures of 10 were determined by X-ray diffraction analysis. The molecule took the desired ant/ conformation around the Si-Si bond. The length of the Si--Si bond is 0.2343(3)nm, which is essentially identical to that in the cyclic structure of 1[0.2346(4) tun]. This result unambiguously demonstrates that the Si--Si bond in the cyclic structure of 1 is not subject to obvious strain.     

Synthesis,Characterization and Crystal Structure of (PhCH2)2Sn(S2CENt2) and (PhCH2)2Sn(S2CNC4H8)2

Two new dibenzyltin bisditiocarbamates(PhCH2)2 Sn(S2CNEt2)2(1) and (PhCH2)2 Sn(S2CNC4H8)2(2) were synthesized by the reaction of dibenzyltin dichloride with dithiocarbamates and characterized by elemental analysis ,IR,^1H NMR and MS spectra.The crystal structures were determined by X-ray single crystal diffraction analysis.In both complexes,the tin atom is six-coordinated in a distorted octahedral configuration.In the crystals of 1,the molecular packing in unit cell reveals that the two adjacent molecules are symmetrically linked to each other in dimers by two Sn S interactions of 0.3816nm.In the crystals of 2,the molecules are packed in the unit cell in one-dimensional chain structure linked by weaker intermolecular S S conmtacts.     

Synthesis, Spectroscopic Properties and Crystal Structures of Dibenzyltin（IV） Dithiobenzoate and Chlorodibenzyltin（IV） Thiobenzoate

Two dibenzyltin(IV) complexes with thiobenzoate ligand, (PhCH2)2Sn(SOCPh)2 (1) and (PhCH2)2Sn(C1)SOCPh (2), have been synthesized by the reaction of dibenzyltin(IV) dichloride with thiobenzoic acid in the presence of organic base Et3N and characterized by IR, ^1H NMR spectroscopy and elemental analysis. Their crystal structures were determined by X-ray single crystal diffraction analysis. In the crystals of 1, the tin atom is six-coordinated in a distorted octahedron configuration. In the crystals of 2, the molecular packing in unit cell reveals that the two adjacent molecules are symmetrically linked to each other to form a dimer with intermolecular Sn…C1 distances of 0.3591 (2) nm and the tin atom is five-coordinated in a distorted trigonal bipyramid configuration.     

Synthesis, Characterization and Crystal Structure of （Z）-1-[2-（Triarylstannyl）vinyl]-1-indanols and Their Arylhalostannyl Derivatives

(Z)-1-[2-(Tri-o-tolylstannyl)vinyl]-1-indanol (1) and (Z)-1-[2-(tri-p-tolylstannyl)vinyl]-l-indanol (2) were synthesized by the addition reaction of 1-ethynylindanol with tri-o-tolyltin and tri-p-tolyltin hydride. The aryl groups in compound 1 and 2 were substituted by Br2 or I2 to yield monohalide derivatives (3-6). The compounds 1-6 were characterized by elemental analysis, ^1H NMR and FT-IR spectroscopy. The crystal structures of 1, 2 and 4 have been determined by single crystal X-ray diffraction analysis. The Sn atom in 1 and 2 exhibits a tetrahedral geometry distorted towards trigonal bipyramid due to a weak intramolecular interaction between Sn and the hydroxyl O atoms [0.2839(4) nm and 0.2744(5) nm], while the Sn atom in 4 adopts a trigonal bipyramidal geometry with a significant O→Sn(1) interaction [0.2552(5) nm].     

Thermal Behavior and Decomposition Kinetics of the Complexes of CuX2 （X=NO3, Br, CI and CIO4） with 3,3＇-Dimethyl-1 -（1 H-1,2,4-triazol-1-yl）-2-butanone

The thermal behaviors of the complexes of Cu(DMTZB)4X2 (DMTZB=3,3‘-dimethyl-1-(1H-1,2,4-triazol-1-yl)-2-butanone, X=NO3 or ClO4) and Cu(DMTZB)2 X2 (X=Br or Cl) in a nitrogen atmosphere were studied under the non-isothermal conditions by simultaneous TG-DTG-DSC, EDS and elemental analysis techniques. The resuits showed that their decomposition proceeded in three different ways mainly depending on the anions in the molecules. The heat effect associated with the decomposition step of DMTZB molecules was also different. The decomposition mechanisms and the kinetic parameters of DMTZB were determined and calculated by jointly using four methods, which showed that its pyrolysis was controlled by D3 mechanism but with different activation energies and pre-exponential factors for different complexes.     

Synthesis, Crystal Structure, Fluorescence Property and Antibacterial Activity of Two Unprecedented One-dimensional Chain Metal organic Coordination Polymers： Zn（H-SSA）（Phen）（H20）2 and Cu（H-SSA） （Phen） （H20）2

The reaction of 5-sulfosalicylic acid(H3-SSA) with o-phenanthroline(Phen),NaOH,and Mcl2(M=Zn,Cu) affords Zn(H-SSA)(Phen)(H2O)2(1) and Cu(H-SSA)(Phen)(H2O)2 (2),respectively ,compounds 1 and 2 are characterized by elemental analysis,IR,fluorescence spectra and single crystal Xray diffraction analysis.The X-ray diffraction analyses reveal that compounds 1 and 2 are isostructure.The 5-sulfosalicylic acid ligand loses two protons at the sulfo-group and carboxylic group during the reaction.The Zn(II) and Cu(II)ions are sixcoordinated and adopt distorted octahedral geometry,which are surrounded by two N atoms from Phen,two O atoms from two water molecules,one O atom from-SO3 group and one oxygen from carboxylic group of the other H-SSA.Compounds 1 and 2 have unprecedented one-dimensional linear chain formed by a repeating mononuclear structureal unit.which is bridged by H-SSA.The fluorescence intensity of 1 and 2 is stronger than that of Phen and H3-SSA at 400nm.The lowest excited single states of these complexes are assigned as mainly Phen localized 1(π π),The antibacterial activity test shows that compounds 1 and 2 strongly inhibit the growth of Streptococcus haemolyticus,Straphylococcus aureus and Escherichia coli.     

Diorgano, Dichloro－tin （IV） Complexes of 4－X－Benzohydroxamic Acid （X=CI, OCH3）： Synthesis, Characterization, Antitumor Activity in Vitro and the Crystal Structure of trans－ [Me2Sn（L2） 2]

A series of diorganotin (IV) derivatives of R2SRL2 (R = Me, Et, n-Bu, ph or CI; L = Ll or L2) and their corresponding mixed-ligand complexes RESn (L1)(L2) have been prepared and the structure of trans-MeESn (L2)2 was characterized by FT-IR, ^1H, ^13C and ^ll9Sn NMR spectroscopies,MS, elemental analysis, melting points and X-ray diffIaction. The structure-activity relationships were discussed.     

Structural and Spectroscopic Studies on [Cu（DACH）2（H2O）]—Cl2（DACH—1,4—Diazacycloheptane）

A penta-coordinated Cu(Ⅱ） complex with 1,4-diazacycloheptane (DACH),[Cu(DACH)2(H2O)]Cl2(1),has been synthesized and characterized by X-ray diffraction,IR spectra,elemental analyses,thermal analyses,UV-Vis and ESR techniques.Complex 1 crystallizes in orthorhombic crystal system,Pbcn space group with a=1.6075(4),b=1.0539(3),c=0.9195(3)nm,V=1.5578(7)nm^3,Mr=352.79,Z=4,Dc=1.487g/cm^3,final R=0.0451 and wR=0.1294.The structure of 1 indicates that the central Cu(Ⅱ） atom is penta-coordinated by four nitrogen aboms of two DACH moieties at the equatorial positions and a water molecule at the axis position.The coordination geometry of Cu(Ⅱ） could be considered as an approximately ideal square-pyramidal environment.Both DACH rings arrange in cis-form and are predominantly in the boat-boat conformation (80%) with some disorder to the chair-chair conformation (20%).The Cl^- anions are hydrogen bonded with the nitrogen donors of the DACH rings and the oxygen donor of the coordinated H2O molecule to form a one-dimensional zigzag linear structure. The solution behaviors of 1 are also discussed in detail by Uvvis and ESR technique.     

Syntheses and Anti—inflammatory Actiobn of （η—C5H5）2Ti （Cin）2 and （η—C5H5）2Ti（Tzea）2

Two new Complexes(Cp)2Ti(Cin)2and (CP2)Ti(Tzea)2(CP=Cyclopentadienyl η^5-C5H5)have been synthesized in THF by the reaction of HCin(Cincofen,2-phenylquinoline-4-carboxylic acid)or HTzea(5-phenyltetrazolyl-2-ethanoic acid)with(Cp)2TiCl2,and characterized by elemental analyses,IR,1H NMR and 13C NMR,UV spectra,molar conductivity,TGDTA.In the complexes the carboxyl groups are coordinated to Ti(IV)in a monodentate manner,The inhibitory actions of the complexes on mice ear tumefaction caused by croton oil and the rat foot granulation growth produced by cotton wool are higher than those of the corresponding ligands HCin,HTzea and [(Cp)2TiCl2],while their toxicities are lower than those of the free ligands.ηη     

Synthesis and Structure of Mixed Distannoxane Dimers [ClR_2SnOSnR''''_2Cl]_2

1,1,3,3-Tetraorganodistannoxanes [XR2SnOSnR2X]2 (R = alkyl, Ph; X = halogen, NCS, OAc, OR) are a kind of organotin oxo clusters. They have received considerable attention because they are useful catalysts for many reactions1-5. And recently S. W. Ng reported that [XR2SnOSnR2X]2 (R = Bu, X = OOCCH2SC(O)N(CH2CH2)2O) had more active antitumor activity than cis-platin in vitro6. A characteristic feature of symmetric tetraorganodistannoxanes in the solid state is their dimeriz…     

Synthesis and structures of beta-diketiminatotin(II) halides, an amide and of Sn(=E)[{N(R)C(Ph)}2CH](NR2) (E = S or Se, R = SiMe3)

Treatment of [Li(L1)]2 (1) or K(L2) (2) with SnX2 in Et2O yielded the heteroleptic beta-diketiminatotin(II) halides Sn(L1)Cl (3a), Sn(L1)Br (3b) or Sn(L2)Cl (4), even when an excess of the alkali metal beta-diketiminate was used [L1={N(R)C(Ph)}2CH, L2={N(R)C(Ph)CHC(But)N(R)}, R = SiMe3]. From and half an equivalent each of SnCl2.2H2O and SnCl2, or one equivalent of SnCl2.2H2O, the product was Sn(L3)Cl (5) or Sn(L4)Cl (6), in which one or both of the N-R bonds of L1 had been hydrolytically cleaved; the compound Sn(L5)Cl (7) was similarly obtained from and an equivalent portion of SnCl2.2H2O [L3={N(R)C(Ph)CHC(But)N(H)}, L4={N(H)C(Ph)CHC(But)N(H)} and L5={N(H)C(Ph)}2CH]. The halide exchange between 3a and 3b, studied by two-dimensional (119)Sn{1H}-NMR spectroscopy, is attributed to implicate a (mu-Cl)(mu-Br)-dimeric intermediate or transition state. The 13C{1H}-NMR spectra of or showed two distinct resonances for each group, which coalesced on heating, corresponding to DeltaG(338 K)= 69.4 (3a) or 72.8 (3b) kJ mol(-1). The chloride ligand of was readily displaced by treatment with NaNR2, CF3SO3H or CH2(COPh)2, yielding Sn(L1)X [X = NR2 (8), O3SCF3 (9) or {OC(Ph)}2CH (10)]. Oxidative addition of sulfur or selenium to gave the tin(IV) terminal chalcogenides Sn(E)(L1)(NR2)[E = S (11) or Se (12)]. The X-ray structures of the cocrystal of 3a/3b and of the crystalline compounds 5, 6, 8, 11 and are presented, as well as multinuclear NMR spectra of each of the new compounds.     

XAFS spectroscopic study of Tc2(O2CCH3)4X2 (X = Cl,Br)

Technetium dimers Tc₂(O₂CCH₃)₄X₂ (X =?Cl, Br) were synthesized and studied by X-ray Absorption Fine Structure spectroscopy (XAFS). EXAFS analysis gave for Tc₂(O₂CCH₃)₄Cl₂: d Tc-Tc =?2.18(1) Å, d Tc–Cl =?2.43(1) Å and for Tc₂(O₂CCH₃)₄Br₂: d Tc–Tc =?2.19(1) Å, d Tc-Br =?2.63(1) Å. The Tc Tc separations are in agreement with Raman studies while the Tc–X distances are somewhat larger. Comparison with other Tc(III) quadruply bonded dimers indicates that the carboxylate compounds exhibit larger Tc–Tc separations. The effect of the terminal ligand (nature and position) on the Tc–Tc separation is discussed.     

The dimerization of SnCl2(g): mass spectrometric and theoretical studies

The vaporization of SnCl2(s) was investigated in the temperature range between 382 and 504 K by the use of Knudsen effusion mass spectrometry. The Sn+, SnCl+, SnCl2+, Sn2Cl3+, and Sn2Cl4+ ions were detected in the mass spectrum of the equilibrium vapor. The SnCl2(g) and Sn2Cl4(g) gaseous species were identified, and their partial pressures were determined. The structure and vibrational properties of both species and corresponding fragmentation products were studied applying density functional theory and second-order M?ller-Plesset perturbation theoretical approaches. Molecular parameters yielded thermodynamic functions by the use of statistical thermodynamics. The sublimation enthalpies of SnCl2(g) and Sn2Cl4(g) at 298 K resulting from the second- and third-law methods are evaluated as 130.9 +/- 6.2 kJ mol(-1) and 155.8 +/- 7.3 kJ mol(-1), respectively. The enthalpy changes of the dissociation reactions Sn2Cl4(g) = 2 SnCl2(g) were obtained as delta(d)H degrees(298) = 106.8 +/- 6.2 kJ mol(-1). The corresponding theoretical value amounts to 103.4 kJ mol(-1). The change of monomer properties due to the dimerization reaction is also discussed.     

(N,N, N′, N′-tetramethylethylenediammonium)Cu2X6 (X=Cl,Br): crystal structure and magnetic interactions

Summary The crystal structures of (Me₄enH₂)Cu₂Cl₆ and (Me₄enH₂)Cu₂Br₆ have been determined. The triclinic crystals contain chains of symmetrically bibridged [Cu₂X₆]^2– dimers. Within the dimers the Cu–X distances average 2.299 Å (Cl) and 2.408 Å (Br) and the Cu–X–Cu angles are 96.4(1)^o (Cl) and 95.7(1)^o (Br). Longer Cu–X bonds, 2.679(1)Å (Cl) and 2.761(3)Å (Br), link dimers together into infinite chains via asymmetrical bridges. The bridging angles for the asymmetric bridge are 92.2(1)^o (Cl) and 89.4(1)^o (Br). Magnetic susceptibility data for both compounds are indicative of antiferromagnetic coupling. Analyses of the data yields J/k=–23(1)K (Cl) and –82(2)K (Br) for the interdimer coupling and J/k=–5(1)K (Cl) and –4(1)K (Br). The intradimer coupling for the chloride is in accord with magneto-structure relations deduced for similar salts. Similarly, the increased antiferromagnetic contribution upon substitution of Cl by Br follows trends previously observed.     

1,3 Dichloro- and 1,3 dibromotetra-n-butyldistannoxane mixtures: ligand redistribution and fluxional dynamics in distannoxanes

The halogen redistribution reaction in the binary [ⁿBu₂SnCl]₂O/[ⁿBu₂SnBr]₂O system is examined by ¹¹⁹Sn- and ¹³C-NMR spectroscopy. Binary mixtures of [ⁿBu₂SnCl]₂O and [ⁿBu₂SnBr]₂O reach equilibrium rapidly at room temperature. The reactant dimers are found to be in equilibrium with all five possible mixed distannoxane dimers in the equimolar mixture. These mixed distannoxane dimers differ in the ratio of Cl and Br as well as the relative positioning of the halogens. The mechanism responsible for the rapid formation of the mixed Cl:Br distannoxane dimers is found to proceed via bimolecular collisions producing a four-centered transition state, which in turn undergoes a concerted exchange of the halogens. The equilibrium concentrations of the reactant and product dimers are well represented by a statistical distribution, indicating that Cl and Br exhibit equivalent donor abilities. At 298 K, the NMR spectral data are consistent with time-averaged structures arising from rapidly interconverting rigid ladder pairs. Lowering the temperature to 173 K failed to freeze out this fluxional process. A reversible configurational rearrangement is also observed in which rotation about the oxygen---exocyclic tin bond results in the mutual exchange of halogens associated with the same exocyclic tin atom.     

Nanosecond CO photodissociation and excited-state character of [Ru(X)(X')(CO)2(N,N'-diisopropyl-1,4-diazabutadiene)] (X=X'=Cl or I; X=Me, X'=I; X=SnPh3, X'=Cl) studied by time-resolved infrared spectroscopy and DFT calculations

The character and dynamics of the low-lying excited states of [Ru(X)(X')(CO)2(iPr-dab)] (X=X'=Cl or I; X=Me, X'=I; X=SnPh3, X'=Cl; iPr-dab=N, N'-diisopropyl-1,4-diazabutadiene) were studied experimentally by pico- and nanosecond time-resolved IR spectroscopy (TRIR) and (for X=X'=Cl or I) computationally using density functional theory (DFT) and time-dependent DFT (TD-DFT) techniques. The lowest allowed electronic transition occurs between 390 and 460 nm and involves charge transfer from the Ru(halide)(CO) 2 unit to iPr-dab, denoted (1)MLCT/XLCT (metal-to-ligand/halide-to-ligand charge transfer). The lowest triplet state is well modeled by UKS-DFT-CPCM calculations, which quite accurately reproduce the excited-state IR spectrum in the nu(CO) region. It has a (3)MLCT/XLCT character with an intraligand (iPr-dab) (3)pipi* admixture. TRIR spectra of the lowest triplet excited state show two nu(CO) bands that are shifted to higher energies from their corresponding ground-state positions. The magnitude of this upward shift increases as a function of the ligands X and X' [(I)2 < (Sn)(Cl) < (Me)(I) < (Cl)2] and reveals increasing contribution of the Ru(CO)2-->dab MLCT character to the excited state. The lowest triplet state of [Ru(Cl)2(CO)2(iPr-dab)] undergoes a approximately 10 ps relaxation that is followed by CO dissociation, producing cis(CO,CH 3CN),trans(Cl,Cl)-[Ru(Cl)2(CH 3CN)(CO)(iPr-dab)] with a unity quantum yield and 7.2 ns lifetime and without any observable intermediate. To our knowledge, this is the first example of a "slow" CO dissociation from a thermally equilibrated triplet charge-transfer excited state.     

Experimental and ab initio structural study of the ketotin compounds,X3SnCR2CH2COMe: crystal structures of X3SnCMe2CH2COMe (X = Cl and I)

The MeCOCH₂CMe₂ ligand in X₃SnCMe₂CH₂COMe ( 2 ; X = halide) acts as a C,O‐chelating group both in the solid state and in non‐coordinating solutions. The intramolecular Sn? O bond lengths in trigonal bipyramidal 2 (X = Cl and I), as determined by X‐ray crystallography, indicate that the stronger interaction occurs in 2 X = Cl. Comparisons with the Sn? O bond lengths in the estertin trihalides, X₃SnCH₂CH₂CO₂R ( 1 ; R = Me), suggest that the latter form stronger chelates than do 2 . In chlorocarbon solution, 2 (X = Cl, I) undergoes exchange reactions, as shown by NMR spectra, to give all possible halide derivatives, ∑(Cl_nI_3?nSnCMe₂CH₂COMe) (n = 0–3). Various ab initio calculations on 2 and X₃SnCH₂CH₂COMe ( 3 ) have been carried out. Comparisons of the theoretical and experimental structures of 2 for X = Cl or I are reported. Copyright © 2005 John Wiley & Sons, Ltd.     

Preparation and structural characterization of ionic five-coordinate palladium(II) and platinum(II) complexes of the ligand tris[2-(diphenylphosphino)ethyl]phosphine. Insertion of SnCl(2) into M-Cl bonds (M = Pd,Pt) and hydroformylation activity of the Pt-SnCl(3) systems

The five-coordinate palladium(II) and platinum(II) complexes [M(PP(3))Cl]Cl [M = Pd (1), Pt (2)] (PP(3) = tris[2-(diphenylphosphino)ethyl]phosphine) were prepared by interaction of aqueous solutions of MCl(4)(2-) salts with PP(3) in CHCl(3). Complexes 1 and 2 undergo facile chloro substitution reactions with KCN in 1:1 and 1:2 ratios to afford complexes [M(PP(3))(CN)]Cl [M = Pt (3)] and [M(PP(3))(CN)](CN) [M = Pd (4), Pt (5)] possessing M-C bonds, both in solution and in the solid state. The reaction of 1 and 2 with SnCl(2) in CDCl(3) occurs with insertion of SnCl(2) into M-Cl bonds leading to the formation of [M(PP(3))(SnCl(3))](SnCl(3)) [M = Pd (6), M = Pt (7)]. The isolation as solids of complexes 6 and 7 by addition of SnCl(2) to the precursors requires the presence of PPh(3) which activates the cleavage of M-Cl bonds, favors the SnCl(2) insertion, and does not coordinate to M in any observable extent. Solutions of 6 in CDCl(3) undergo tin dichloride elimination in higher proportion than solutions of 7. The reaction of complexes 1 and 2 with SnPh(2)Cl(2) leads to [M(PP(3))Cl](2)[SnPh(2)Cl(4)] [M = Pd (8)]. Complexes 2, 5, 7, and 8 were shown by X-ray diffraction to contain distorted trigonal bipyramidal monocations [M(PP(3))X](+) [M = Pt, X = Cl(-) (2), X = CN(-) (5), X = SnCl(3)(-) (7); M = Pd, X = Cl(-) (8)], the central P atom of PP(3) being trans to X in axial position and the terminal P donors in the equatorial plane of the bipyramids. The "preformed" catalyst 7 showed a relatively high aldehyde selectivity compared to most of the platinum catalysts.     

Beiträge zur Chemie des Phosphors. 152. Funktionalisierte Cyclotriphosphane des Typs (t-BuP)2PX (X = K,SiMe3, SnMe3, Cl,Br, PCl2, P(t-Bu)Cl,P(t-Bu)I)

Contributions to the Chemistry of Phosphorus. 152. Functionalized Cyclotriphosphanes of the Type (t-BuP)₂PX (X = K, SiMe₃, SnMe₃, Cl, Br, PCl₂, P(t-Bu)Cl, P(t-Bu)I) Functionalized cyclotriphosphanes of the type (t-BuP)₂PX with electropositive or electronegative substituents X have been prepared on various synthetic routes: KP(t-BuP)₂ ( 1 ) can be obtained in 50–55 per cent purity by reacting (t-BuP)₄ or (t-BuP)₃ with potassium. Reaction of 1 with Me₃SiCl or Me₃SnCl leads to the cyclotriphosphanes (t-BuP)₂PSiMe₃ ( 2 ) and (t-BuP)₂PSnMe₃ ( 3 ), respectively; the cyclocondensation of Cl(t-Bu)P? P(t-Bu)Cl with P(SnMe₃)₃, however, is more convenient for the preparation of 3 . In a similar way the halogenated compounds (t-BuP)₂PCl ( 4 ) and (t-BuP)₂PBr ( 5 ) can be obtained from Me₃Sn(t-Bu)P? P(t-Bu)SnMe₃ ( 6 ) and PX₃ (X = Cl, Br). The phosphino-substituted cyclotriphosphanes (t-BuP)₂P? PCl₂ ( 7 ), (t-BuP)₂P? P(t-Bu)Cl ( 8 ), and (t-BuP)₂P? P(t-Bu)I ( 9 ) are accessible by the reaction of 3 with PCl₃ and t-BuPX₂ (X = Cl, I), respectively. 2–9 could be obtained free from phosphorus-containing by-products and were ³¹P-NMR spectroscopically characterized as compounds with a cyclic P₃ skeleton.