Pt羰基簇合物在NaY内的合成机理

利用IR，EXAFS, ~(13)CO同位素交换反应及与NO作用等手段研究了Pt羰基簇合物[Pt_3(CO)_6]~(2-)_n(n＝3,4)在NaY分子筛超笼内的合成机理．在氧化样品Pt~(2+)/NaY上300－373 K的还愿羰基化过程中，首先Pt~(2+)与CO反应生成PtO(CO)物种(波数σ_(CO)＝2110 cm~(-1))，然后聚集成“Pt_3(CO)_6”(σ_(CO)＝2112，1896和1841 cm~(-1))，最后生成深绿色的Pt羰基簇合物Pt_(12)(CO)_(24)]~(2-)/NaY(σ_(CO)＝2080，1824 cm~(-1))．“Pt_3(CO)_6”的羰基在室温下能迅速地与~(13)CO发生交换，而[Pt_3(CO)_6]~(2-)_n(n＝3,4)的羰基与~(13)CO的同位素交换即使在343 K也进行得很慢，室温下，NO能逐步破坏Pt羰基簇合物的层间和层内Pt－Pt键，得到中间物种“Pt_3(CO)_6”和PtO(CO)，同时在气相产生CO_2和N_2O．而由上述两中间物种出发，300－353 K温度下，在CO气氛中的还原羰基化又能可逆地得到原羰基簇合物．     

NaY超笼内[Pt_3(CO)_3(μ_2-CO)_2]_n~(2-)(n=3,4)簇合物的合成、表征及其催化CO+NO的反应性能

在NaY分子筛超笼内合成了桔黄色的[Pt_9(CO)_(18)]~(2-)和深绿色的[Pt_(12)(CO)_(24)]~(2-)簇合物。前者给出2056和1798cm~(-1)的线式和桥式羰基特征红外谱带;后者给出2080和1824cm~(-1)谱带。与在THF溶液中结果相比,NaY内合成的羰基簇合物的线式v_(CO)向高波数位移,而桥式v_(CO)向低波数位移。EXAFS为Pt羰基簇合物在分子筛内的规整形成提供了证据。NaY内Pt_9和Pt_(12)羰基簇合物在NO+CO反应中显示了较高的催化活性及稳定性。     

膦取代的羰基铂簇的合成,结构和性质

Pt(PPh_3)_2Cl_2在碱性介质中,与一氧化碳直接进行还原及羰基化反应,得到五种膦取代的羰基铂配合物:Pt_5(μ_2-CO)_5(CO)(PPh_3)_4 1,Pt_3(μ_2-CO)_3(PPh_3)_3 2,Pt_3(μ_2-CO)_3(PPh_3)_4 3,Pt_4(μ_2-CO)_5(PPh_3)_4 4,以及Pt(Cl)(PPh_3)_2(COOCH_3) 5。经X-射线单晶衍射分析,确定了新的三核铂羰基簇2以及配合物5的分子结构。还讨论了1和5的生成机理。     

由担载 Pt_3(CO)_3(PPh_3)_4络合物制备的Pt催化剂表面性质的研究

本文以CO为探针,采用红外光谱、电子自旋共振谱、化学吸附及其程序升温脱附等方法,研究了由担载于Al_2O_3和TiO_2上的Pt_3(CO)_3(PPh_3)_4络合物制成的分散型Pt 催化剂的表面性质和金属与载体间的相互作用。实验结果表明,由Pt_3(CO)_(PPh_3)_4/Al_2O_3表面络合物在真空中脱羰基后所得Pt催化剂吸附CO的IR谱带位于1800cm~(-1),2010cm~(-1)左右,分别对应于桥式(B-)和线式(L-)CO吸附态,B/L值与由无机酸制备之催化剂相比较大。当催化剂经过氧化-还原处理后,由于吸附CO 的B/L 值减小而与无机酸制得之催化剂相近。与此相反,对以TiO_2为载体的催化剂,不论在真空抑或CO中脱羰基时,吸附CO的IR谱不出现桥式态。IR与CO化学吸附量测定结果还表明,由TiO_2为载体的Pt催化剂随氢还原温度之升高CO化学吸附量减少,相应地其CO IR谱带强度逐渐减弱并向低波数方向位移,相应的TPD峰位置却向高温方向位移。     

担载的Pt3(CO)3(PPh3)4络合物的红外光谱研究

在分子水平上,研究担载过渡金属簇羰基络合物在担载及活化时的结构变化过程,不但有助于系统了解固载的过渡金属簇羰基络合物的表面金属有机化学,还可以获得制备高分散金属簇催化剂的信息.目前研究比较多的担载过渡金属簇羰基络合物是Fe,Os,Rh等络合物,对Pt簇络合物的研究比较少.其中Ichikawa研究了担载的[Pt_3(CO)_6]_n·NEt_4(n=1—5)的红外光谱和络合物分解后CO的吸附态及金属分散度.     

金属羰基络合物制备的Pt-Re/Al_2O_3催化剂的性能 Ⅱ 不同方法制备的Pt-Re/Al_2O_3催化剂的物化性质表征

采用TPR,H_2化学吸附,TPD,TEM和DRS等方法对一组组成相同制法不同的Pt-Re/Al_2O_3催化剂进行了表征。TPR,H_2化学吸附等结果表明,Pt-Re/Al_2O_3催化剂中Re是通过与Pt的相互作用形成有高温吸附H_2中心及抗积炭能力的Pt-Re集团,从而提高了重整催化剂的活性和稳定性。制备方法的不同对催化剂活性表面的形成及铂铼相互作用有重要影响。以羰基金属原子簇化合物制备的Pt_5Re_2催化剂的Pt和Re的相互作用程度最大,这种相互作用从TPR和DRS测定中得到验证。电镜观察发现Pt_5Re_2催化剂表面的金属晶粒分布比常规Pt-Re小且均匀。由于担载羰基化合物在脱羰过程中CO发生歧化生成的微量碳物类使Pt_5Re_2具有较好的活性、芳构化选择性和稳定性。     

ArCCo~3(CO)~9~-~nL~n的化学ETC合成及其电化学研究

利用由化学还原剂BPK引发的电子迁移催化反应(ETC)合成了两个系列八种新的三核钴簇合物p-RC_6H_4CCo_3(CO)_(9-n)L_n(L=PPh_3,n=1;L=P(OEt)_3,n=2)。用m.p.、元素分析、IR及~1H NMR对簇合物进行了表征。对簇合物在Pt电极上的循环伏安(CV)研究表明,p-RC_6H_4CCo_3(CO)_9及PPh_3单取代物在室温下均经历一个可逆的单电子过程。p-RC_6H_4CCo_3(CO)_9的E_(1/2)与R的σ_m的线性关系表明R通过诱导效应影响簇合物的氧化还原性。取代簇合物的还原电势相对于母体簇合物的负移表明P的配位增大了CCo_3上的电荷密度,导致簇合物难被还原。     

ArCCo~3(CO)~9~-~nL~n的化学ETC合成及其电化学研究

利用由化学还原剂BPK引发的电子迁移催化反应(ETC)合成了两个系列八种新的三核钴簇合物p-RC~6H~4CCo~3(CO)~9~-~nL~n(L=PPh~3, n=1; L=P(OEt)~3, n=2)。用m.p.、元素分析、IR及^1H NMR对簇合物进行了表征。对簇合物在Pt电极上的循环伏安(CV)研究表明, p-RC~6H~4CCo~3(CO)~9及PPh~3单取代物在室温下均经历一个可逆的单电子过程。p-RC~6H~4CCo~3(CO)~9的E~1~/~2与R的σ~m线性关系表明R通过诱导效应影响簇合物的氧化还原性。取代簇合物的还原电势相对于母体簇合物的负转移表明P的配位增大了CCo~3上的电荷密度, 导致簇合物难被还原。     

分子筛负载的Ru3(CO)12催化剂的结构与性能

催化剂是通过真空蒸气浸渍的方法把Ru_3(CO_(12))负载在NaY分子筛载体上制备的,同时研究了由Ru_3(CO)_(12)/NaY转变为高分散的、NaY负载的钌金属簇催化剂的变化过程及其变态形式。环丙烷在Ru_3(CO_(12))/NaY上的氢解作用表明,即使微型反应器中的温度不超过136℃,羰基络合物已发生了完全的脱羰作用和金属的大量烧结。然而,NaY负载的钌金属簇催化剂和Al_2O_3负载的钌催化剂相比,对于环丙烷氢解为丙烷以及丁烯-1的氢化异构化两个反应,呈现出完全不同的催化活性和产品选择性,并且在此反应条件下催化稳定性较好。     

担载四核羰基簇——FeCo_3(CO)_11PPh_3~-在聚苯乙烯表面簇骼畸变的EXAFS研究

通过配体取代将四核羰基簇FeCo_3(CO)_(12)~-锚联在膦化的聚苯乙烯表面,获得担载簇FeCo(?)(CO)_(11)PPh_3~-/poly,目的在于使簇骼结构偏离较高对称性.以考察锚联过程对簇结构的影响.本文以EXAFS(Extended X-ray Absorption Fine Structure)方法研究了担载样品的结构.结果显示担载簇与FeCo_3(CO)_(11)PPh_3~-晶体具有相同的结构模式,尤其是膦配体确实与一Co原子相连接.EXAFS结果表明:(1)与FoCo_3(CO)_(12)~-(其簇骼具有三重对称性结构)比较,锚联使Co—Fe键增长0.005nm;金属-金属及金属-桥联碳壳层的Debye-Waller因子均增大约一倍而金属-端联碳壳层的值变化很小.说明金属-金属间实际键长值具有一较宽分布,因而其簇骼已偏离了三重对称结构;(2)与FeCo_3(CO)_(11)PPh_3~-晶体的结构比较.Co—Fe键长长0.003nm.而Co—Co键长则短约0.002nm.考虑到EXAFS分析只能给出平均键长值,因此认为,存在于FeCo_3(CO)_(11)PPh_3~-晶体中的由于一个羰基被膦配体取代而引起的簇骼畸变,在锚联后被加剧.     

New high-nuclearity Ni-Pt carbonyl clusters: synthesis and X-ray structure of the ordered [HNi24Pt17(CO)46]5- and the substitutionally Ni/Pt disordered [Ni32Pt24(CO)56]6- cluster anions

Condensation between preformed Ni-Pt and Pt carbonyl clusters leads to the new [H(6-n)Ni(24)Pt(17)(CO)(46)](n-)(n= 5, 6) and the substitutionally Ni/Pt disordered [Ni(24)(Ni(12-x)Pt(x))Pt(20)(CO)(56)](6-) (x = 4) carbonyl clusters, the latter of which represents the highest nuclearity homoleptic carbonyl cluster anion so far reported.     

Asymmetrical A-Frame Triplatinum Clusters Bridged by Small Organic Molecules and Bis((diphenylphosphino)methyl)phenylphosphine

Reactions of the linear triplatinum complex [Pt(3)(&mgr;-dpmp)(2)(XylNC)(2)](2+) (3) with small organic molecules led to formation of asymmetrical A-frame triplatinum complexes with an additional bridge across one of the metal-metal bonds, where dpmp is bis((diphenylphosphino)methyl)phenylphosphine. Reaction of complex 3 with electron deficient alkynes (R(1)C&tbd1;CR(2): R(1) = R(2) = CO(2)Me; R(1) = H, R(2) = CO(2)Me; R(1) = R(2) = CO(2)Et) afforded a new series of triplatinum clusters formulated as [Pt(3)(&mgr;-dpmp)(2)(&mgr;-R(1)CCR(2))(XylNC)(2)](PF(6))(2) (5a, R(1) = R(2) = CO(2)Me; 5b, R(1) = H, R(2) = CO(2)Me; 5c, R(1) = R(2) = CO(2)Et) in good yields. The complex cation of 5b was characterized by X-ray crystallography to have an asymmetrical A-frame structure comprising three Pt atoms bridged by two dpmp ligands, in which an acetylene molecule was inserted into one of the Pt-Pt bonds (triclinic, P&onemacr;, a = 19.507(3) ?, b = 20.327(4) ?, c = 14.499(4) ?, alpha = 107.69(2) degrees, beta = 102.08(2) degrees, gamma = 71.30(1) degrees, V = 5148 ?(3), Z = 2, R = 0.070, and R(w) = 0.084). The Pt-Pt bond length is 2.718(1) ? and the Pt.Pt nonbonded distance is 3.582(1) ?. Treatment of 3 with an excess of HBF(4).Et(2)O gave the asymmetrical cluster [Pt(3)(&mgr;-dpmp)(2)(&mgr;-H)(XylNC)(2)](BF(4))(3).CH(2)Cl(2) (6.CH(2)Cl(2)), in 61% yield, and a similar reaction with p-NO(2)C(6)H(4)NC led to the formation of [Pt(3)(&mgr;-dpmp)(2)(&mgr;-R(3)NC)(XylNC)(2)](PF(6))(2).CH(2)Cl(2) (7.CH(2)Cl(2)) in 94% yield (R(3) = p-NO(2)C(6)H(4)). Complexes 6 and 7 are assumed to have a single atom-bridged, asymmetrical A-frame structures. Reaction of the complex syn-[Pt(2)(&mgr;-dpmp)(2)(XylNC)(2)](2+) (1) with [MCl(2)(cod)] (M = Pt, Pd) gave the dimer-monomer combined trinuclear cluster [Pt(2)MCl(2)(&mgr;-dpmp)(2)(XylNC)(2)](PF(6))(2) (8a, M = Pt, 89%; 8b, M = Pd, 55%). The structure of 8a was determined by X-ray crystallography to be comprised of a metal-metal-bonded diplatinum core and a monomeric platinum center bridged by two dpmp ligands with a face-to-face arrangement (triclinic, P&onemacr;, a = 18.082(7) ?, b = 19.765(6) ?, c = 15.662(4) ?, alpha = 98.51(2) degrees, beta = 94.24(3) degrees, gamma = 109.82(2) degrees, V = 5161 ?(3), Z = 2, R = 0.069, and R(w) = 0.080). The Pt-Pt bond length is 2.681(2) ? and the Pt.Pt nonbonded distance is 3.219(2) ?. The heteronuclear complex 8b was transformed to an A-frame trinuclear cluster, [Pt(2)PdCl(&mgr;-Cl)(&mgr;-dpmp)(2)(XylNC)](PF(6))(2) (9), which was characterized by X-ray crystallography (monoclinic, C2/c, a = 33.750(9) ?, b = 28.289(9) ?, c = 23.845(8) ?, beta = 118.19(4) degrees, V = 20066 ?(3), Z = 8, R = 0.082, and R(w) = 0.077). The diplatinum unit (Pt-Pt = 2.606(2) ?) is connected to the mononuclear Pd center by a chloride bridge (Pt.Pd = 3.103(3) ?, Pt-Cl-Pd = 79.6(3) degrees ).     

Analysis of in situ EXAFS data of supported metal catalysts using the third and fourth cumulant

X-Ray absorption spectra of supported Pt catalysts with various Pt cluster sizes were collected between 77 and 673 K, in inert and hydrogen atmospheres. When analyzing these spectra with the standard EXAFS equation, a Pt-Pt bond contraction and a large increase in the inner potential correction were observed with increasing temperature. These errors are up to 0.08 A and 10 eV for clusters of 1 nm diameter. They were corrected by including the third and fourth cumulants as fit parameters. Fit guidelines were developed to analyze EXAFS data of supported metal catalysts collected at elevated temperatures, allowing for asymmetry and broadening or sharpening of the pair distribution function. These comprise fixing fit parameters, using different k-weightings and identifying trends in a series of experiments. By fitting the EXAFS spectra using these guidelines, it was determined that in small Pt clusters the Pt-Pt bond is 0.10 A shorter than in bulk Pt. These contracted bonds relax to distances near that of bulk Pt upon hydrogen chemisorption.     

Synthesis and characterisation of nu3-octahedral [Ni36Pd8(CO)48]6- and [Ni35Pt9(CO)48]6- clusters displaying unexpected surface segregation of Pt atoms and molecular and/or crystal substitutional Ni/Pd and Ni/Pt disorder

The synthesis and structure, as well as the chemical and electrochemical characterisation of two new nu(3)-octahedral bimetallic clusters with the general [Ni(44-x)M(x)(CO)(48)](6-) (M = Pd, x = 8; M = Pt, x = 9) formula is reported. The [Ni(35)Pt(9)(CO)(48)](6-) cluster was obtained in reasonable yields (56 % based on Pt) by reaction of [Ni(6)(CO)(12)](2-) with 1.1 equivalents of Pt(II) complexes, in ethyl acetate or THF as the solvent. The [Ni(36)Pd(8)(CO)(48)](6-) cluster was obtained from the related reaction with Pd(II) salts in THF, and was isolated only in low yields (5-10 % based on Pd), mainly because of insufficient differential solubility of its salts. The unit cell of the [NBu(4)](6)[Ni(35)Pt(9)(CO)(48)] salt contains a substitutionally Ni-Pt disordered [Ni(24)(Ni(14-x)Pt(x))Pt(6)(CO)(48)](6-) (x = 3) hexaanion. A combination of crystal and molecular disorder is necessary to explain the disordering observed for the Ni/Pt sites. The unit cell of the corresponding [Ni(36)Pd(8)(CO)(48)](6-) salt contains two independent [Ni(30)(Ni(8-x)Pd(x))Pd(6)(CO)(48)](6-) (x = 2) hexaanions. The two display similar substitutional Ni-Pd disorder, which probably arises only from crystal disorder. The structure of [Ni(36)Pd(8)(CO)(48)](6-) establishes the first similarity between the chemistry of Ni-Pd and Ni-Pt carbonyl clusters. A comparison of the chemical and electrochemical properties of [Ni(35)Pt(9)(CO)(48)](6-) with those of the related [Ni(38)Pt(6)(CO)(48)](6-) cluster shows that surface colouring of the latter with Pt atoms decreases redox as well as protonation propensity of the cluster. In contrast, substitution of all internal Pt and two surface Ni with Pd atoms preserves the protonation behaviour and is only detrimental with respect to its redox aptitude. A qualitative rationalisation of the different surface-site selectivity of Pt and Pd, based on distinctive interplays of M--M and M--CO bond energies, is suggested.     

Chiral and achiral phosphine derivatives of alkylidyne tricobalt carbonyl clusters as catalyst precursors for (asymmetric) inter- and intramolecular Pauson-Khand reactions

Phosphine derivatives of alkylidyne tricobalt carbonyl clusters have been tested as catalysts/catalyst precursors in intermolecular and (asymmetric) intramolecular Pauson-Khand reactions. A number of new phosphine derivatives of the tricobalt alkylidyne clusters [Co3(micro3-CR)(CO)9] (R = H, CO2Et) were prepared and characterised. The clusters [Co3(micro3-CR)(CO)9-x(PR'3)x] (PR'3 = achiral or chiral monodentate phosphine, x = 1-3) and [Co3(micro3-CR)(CO)7)(P-P)] (P-P = chiral diphosphine; 1,1'- and 1,2-structural isomers) were assayed as catalysts for intermolecular and (asymmetric) intramolecular Pauson-Khand reactions. The phosphine-substituted tricobalt clusters proved to be viable catalysts/catalyst precursors that gave moderate to very good product yields (up to approximately 90%), but the enantiomeric excesses were too low for the clusters to be of practical use in the asymmetric reactions.     

Synthesis and Characterization of a Series of Triethylphosphine-Ligated Pt-Au Cluster Compounds. X-ray Crystal and Molecular Structure of [Pt(AuPEt(3))(9)](NO(3))(3)

The first triethylphosphine-stabilized Pt-Au cluster compounds, [Pt(AuPEt(3))(10)](2+) (2) and [Pt(AuPEt(3))(9)](3+) (3), were prepared by the direct reaction of Pt(PEt(3))(3) with AuPEt(3)NO(3) under a dihydrogen atmosphere. Cluster 2 is the highest-nuclearity homoleptic Pt(AuPR(3))(n)() cluster yet prepared. The reactivity and structures of these clusters are in agreement with the well-established electron-counting arguments. The 18-electron cluster 2 was converted into the 16-electron cluster 3 by oxidation with 2 equiv of ferricinium ion [Fe(eta(5)-C(5)H(5))(2)](+). Cluster 3 was converted into 2 by reduction with H(2) in the presence of [AuPEt(3)](+). Cluster 3 was also observed to cleanly add the 2-electron donors CO and PEt(3) to form the 18-electron clusters [(CO)Pt(AuPEt(3))(9)](3+) (4) and [(PEt(3))Pt(AuPEt(3))(9)](3+) (5), respectively. Single-crystal X-ray diffraction results show that 3 has a flattened, toroidal structure in which the PtAu(9) framework has a Pt-centered, tricapped trigonal prismatic geometry. Crystal data for [Pt(AuPEt(3))(9)](NO(3))(3) is as follows: hexagonal P6(3)/m, a = 15.134(5) ?, c = 23.48(1) ?, V = 4657 ?(3), Z = 2, residuals R = 0.056, and R(w)() = 0.053 for 1489 observed reflections and 81 variables, Mo Kalpha radiation. Compound 3 was found to reversibly add H(2) in solution to form the dihydride cluster [(H)(2)Pt(AuPEt(3))(9)](3+) (6). The equilibrium constant for this addition reaction is 1.1 x 10(3) M(-)(1) (CD(2)Cl(2) solution, 25 degrees C), slightly smaller than that for [Pt(AuPPh(3))(8)](2+). The rate of the addition is also slower than that with [Pt(AuPPh(3))(8)](2+). Cluster 3 is an excellent homogeneous catalyst for H(2)-D(2) equilibration giving a turnover rate for HD production of 0.13 s(-)(1) (nitrobenzene solvent, 30 degrees C, 1 atm). The PEt(3)-containing clusters give similar rates and follow the same general trends previously observed with PPh(3)-ligated clusters. The chemistry of these new clusters is explained by consideration of the steric and electronic properties of the PEt(3) ligand. These new compounds will be useful as models for hydrogen activation by Pt-Au clusters and as precursors for supported Pt-Au catalysts.     

The inter-conversions of platinum carbonyl dianionic clusters, [Pt3(CO)6](n)2- (n = 2-5), in THF and acetonitrile. A combined in situ FTIR spectroscopic and BTEM study leading to the characterization of the new [H(4-x)Pt15(CO)19]x- (x = 2-4) clusters

The inter-conversions of platinum carbonyl dianionic clusters, ([Pt(3)(CO)(6)](n)(2-), n = 2-5), have been studied in THF and acetonitrile using in situ FTIR spectroscopy. These inter-conversions were facilitated by the addition (or removal) of molecular hydrogen. The individual reactions, namely reductions and oxidations of [Pt(3)(CO)(6)](n)(2-) were fast and reversible. BTEM analysis of the data provided the pure component spectra of the individual species without the need for physical separation. It is shown, for the first time, that the species [Pt(3)(CO)(6)](n)(2-) (n = 2) can be formed from the reduction of [Pt(3)(CO)(6)](n)(2-) (n = 3-5) by hydrogen alone in acetonitrile. Also, detection of dissolved CO(2) in solution suggests that a room-temperature water gas shift reaction occurs. This has been shown to arise from nucleophilic attack of water on a coordinated CO of [Pt(3)(CO)(6)](n)(2-) which leads to the formation of [HPt(15)(CO)(19)](3-) and [H(2)Pt(15)(CO)(19)](2-). The parent tetraanion, [Pt(15)(CO)(19)](4-), has been isolated in high yields by reaction of [Pt(3)(CO)(6)](n)(2-) (n = 2, 3) with NaOH at 60 °C and has been structurally characterized by X-ray analysis.     

Site selectivity in the reactions of the hexanuclear platinum cluster [Pt6(mu-PtBu2)4(CO)6][CF3SO3]2

The previously reported hexanuclear cluster [Pt(6)(mu-PtBu(2))(4)(CO)(6)](2+)[Y](2) (1-Y(2): Y=CF(3)SO(3) (-)) contains a central Pt(4) tetrahedron bridged at each of the opposite edges by another platinum atom; in turn, four phosphido ligands bridge the four Pt-Pt bonds not involved in the tetrahedron, and, finally, one carbonyl ligand is terminally bonded to each metal centre. Interestingly, the two outer carbonyls are more easily substituted or attacked by nucleophiles than the inner four, which are bonded to the tetrahedron vertices. In fact, the reaction of 1-Y(2) with 1 equiv of [nBu(4)N]Cl or with an excess of halide salts gives the monochloride [Pt(6)(mu-PtBu(2))(4)(CO)(5)Cl](+)[Y], 2-Y, or the neutral dihalide derivatives [Pt(6)(mu-PtBu(2))(4)(CO)(4)X(2)] (3: X=Cl; 4: X=Br; 5: X=I). Moreover, the useful unsymmetrically substituted [Pt(6)(mu-PtBu(2))(4)(CO)(4)ICl] (6) was obtained by reacting equimolar amounts of 2 and [nBu(4)N]I, and the dicationic derivatives [Pt(6)(mu-PtBu(2))(4)(CO)(4)L(2)](2+)[Y](2) (7-Y(2): L=(13)CO; 8-Y(2): L=CNtBu; 9-Y(2): L=PMe(3)) were obtained by reaction of an excess of the ligand L with 1-Y(2). Weaker nitrogen ligands were introduced by dissolving the dichloride 3 in acetonitrile or pyridyne in the presence of TlPF(6) to afford [Pt(6)(mu-PtBu(2))(4) (CO)(4)L(2)](2+)[Z](2) (Z=PF(6) (-), 10-Z(2): L=MeCN; 11-Z(2): L=Py). The "apical" carbonyls in 1-Y(2) are also prone to nucleophilic addition (Nu(-): H(-), MeO(-)) affording the acyl derivatives [Pt(6)(mu-PtBu(2))(4)(CO)(4)(CONu)(2)] (12: Nu=H; 13: Nu=OMe). Complex 12 is slowly converted into the dihydride [Pt(6)(mu-PtBu(2))(4)(CO)(4)H(2)] (14), which was more cleanly prepared by reacting 3 with NaBH(4). In a unique case we observed a reaction involving also the inner carbonyls of complex 1, that is, in the reaction with a large excess of the isocyanides R-NC, which form the corresponding persubstituted derivatives [Pt(6)(mu-tPBu(2))(4)(CN-R)(6)](2+)[Y](2), (15-Y(2): R=tBu; 16-Y(2) (2-): R=-C(6)H(4)-4-C triple bond CH). All complexes were characterized by microanalysis, IR and multinuclear NMR spectroscopy. The crystal and molecular structures of complexes 3, 5, 6 and 9-Y(2) are also reported. From the redox viewpoint, all complexes display two reversible one-electron reduction steps, the location of which depends both upon the electronic effects of the substituents, and the overall charge of the original complex.