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Building upon our earlier results on the chemistry of nido‐1,2‐[(Cp*RuH)2B3H7] (Cp*=ɳ5‐C5Me5) (nido‐1) with different transition metal carbonyls, we continued to investigate the reactivity with group 7 metal carbonyls under photolytic condition. Photolysis of nido‐1 with [Mn2(CO)10] led to the isolation of a trimetallic [(Cp*Ru)2{Mn(CO)3}(μ‐H)(μ‐CO)3(μ3‐BH)] (2) cluster with a triply bridging borylene moiety. Cluster 2 is a rare example of a tetrahedral cluster having hydrido(hydroborylene) moiety. In an attempt to synthesize the Re analogue of 2, a similar reaction was carried out with [Re2(CO)10] that yielded the trimetallic [(Cp*Ru)2{Re(CO)3}(μ‐H)(μ‐CO)3(μ3‐BH)] (3) cluster having a triply bridging borylene unit. Along with 3, a trimetallic square pyramid cluster [(Cp*Ru)2{Re(CO)3}(μ‐H)2(μ‐CO)(μ3,ɳ2‐B2H5)] (4), and heterotrimetallic hydride clusters [{Cp*Ru(CO)2}‐{Re(CO)4}2(μ‐H)] (5) and [{Cp*Ru(CO)}{Re(CO)4}2(μ‐H)3] (6) were isolated. Cluster 4 is a unique example of a M2M′B2 cluster having diboron capped Ru2Re‐triangle. The hydride clusters 5 and 6 have triangular RuRe2 frameworks with one and three μ‐Hs respectively. All the clusters have been characterized by using mass spectrometry, 1H, 11B{1H}, 13C{1H} NMR and IR spectroscopies analyses and the structures of clusters 2–6 have been unambiguously established by XRD analyses. Furthermore, to understand the electronic, structural, and bonding features of the synthesized metal‐rich clusters, DFT calculations have been performed. [ABSTRACT FROM AUTHOR]

The reactivity of κ2‐N,S‐chelated ruthenium borate complexes, [Ru(PPh3)(κ2‐N,S‐(NC7H4S2)Ru{κ3‐H,S,S′‐H2B (NC7H4S2)2}] (1 a) and [Ru(PPh3)(κ2‐N,S‐(NC5H4S){κ3‐H,S,S′‐H2B(NC5H4S)2}] (1 b) with monoboranes have been explored. The prolonged room temperature reaction of [Ru(PPh3){κ2‐N,S‐(NC7H4S2)}{κ3‐H,S,S′‐H2B(NC7H4S2)2}], 1 a with an excess of [BH3 ⋅ THF] led to the formation of hydrogen‐rich complex, arachno‐[PPh3(κ2‐B3H8)Ru{κ3‐H,S,S′‐H2B(NC7H4S2)2] (2). In a similar fashion, the isomeric ruthenatetraborane complexes of [Ru(PPh3)(κ2‐N,S‐(B3H8){κ3‐H,S,S′‐H2B(NC5H4S)2}], 4 and 5 were isolated from the room temperature reaction of 1 b with [BH3 ⋅ THF]. In complex 2, the borate ligand, [H2B(NC5H4S)2] and the PPh3 occupy the endo and exo sites of the butterfly‐shaped RuB3 core, respectively. In contrast, the borate unit [H2B(NC5H4S)2] in 4 sits on the exo position of the butterfly core, while the phosphine ligand occupies the endo site. Multinuclear spectroscopic analyses were done to characterize all new complexes and the structures were further confirmed by single‐crystal X‐ray diffraction analysis. Density functional theory (DFT) calculations were performed to probe into the bonding modes of these complexes. [ABSTRACT FROM AUTHOR]

Synthesis, bonding and chemistry of mono‐ and bimetallic complexes supported by chelating thiolato ligands have been established. Treatment of [Cp*VCl2]3 (1) with [LiBH4 ⋅ THF] followed by the addition of ethane‐1,2‐dithiol led to the formation of an EPR active bimetallic vanadium thiolato complex [(Cp*V){μ‐(SCH2CH2S)‐κ2S,S′)2{V(SCH2CH2S‐SH)}] (2). In complex 2, two ethane‐1,2‐dithiolato ligands are symmetrically coordinated to two vanadium atoms through μ‐S atoms. Interestingly, when similar reactions were carried out with heavier group 5 metal precursors, such as [Cp*NbCl4] (3 a), it afforded monometallic thiolato complex [Cp*Nb(SCH2CH2S)(SCH2CH2S−CH2S)] (4 a). On the other hand, the Ta‐analogue [Cp*TaCl4] (3 b) yielded thiolato species [Cp*Ta(SCH2CH2S)(SCH2CH2S−CH2S)] (4 b) and [Cp*Ta(SCH2CH2S) (SCH2CH2S−S)] (5). In complexes 4 a and 4 b, one ethane‐1,2‐dithiolato and one trithiolato ligand are coordinated to Nb and Ta centers, respectively. Whereas, in complex 5, one ethane‐1,2‐dithiolato and one 2‐disulfanylethanethiolato is coordinated to the Ta center. Moreover, the photolytic reaction of 5 with [Mo(CO)5 ⋅ THF] yielded heterobimetallic thiolato complex [(Cp*Ta){μ‐(SCH2CH2S)‐κ2S,S′}{μ‐(SCH2CH2S−CH2(CH3)S)κ2S′′ : κ1S‐′′′′ : κ1S′′′′′}{Mo(CO)3}] (6). All the complexes have been characterized by multinuclear NMR spectroscopy and single crystal X‐ray diffraction studies. Further, computational analyses were performed to provide an insight into the bonding of these complexes. [ABSTRACT FROM AUTHOR]

A series of triborane and tetraborane analogues have been isolated and structurally characterized utilizing chalcogenatoborate ligands Li[BH3(EPh)] (E=S or Se). Thermolysis of [Cp*TaCl4] in the presence of Li[BH3(SPh)] afforded bimetallic tantallaheteroborane [(Cp*Ta)2(μ‐η3:η3‐B2H4S)(μ‐η2:η2‐SBH3)] (1) and hexasulfido trimetallic complex [(Cp*Ta)3(μ‐S)4(μ‐SPh)2] (2). Compound 1 is a fused ditantallaheteroborane, in which both di‐ and triborane analogues are stabilized by two tantalum atoms. In an attempt to synthesize the selenium analogues of 1 and 2, room‐temperature reaction of [Cp*TaCl4] with Li[BH3(SePh)] was carried out, which afforded bimetallic tantallaheteroborane [(Cp*Ta)2{μ‐η3:η3‐B3H6(SePh)}{μ‐SePh}2] (3), monometallic tantallaheteroboranes [Cp*Ta(SePh)2{B4H8‐n(SePh)n}] (4: n=0, 5: n=1), and trimetallic species [(Cp*Ta)3(μ‐Se)4{μ‐Se2(Se)}] (6). Compound 3 is the rarest example of triborane analogue {B3H6(SePh)} in the coordination sphere of two tantalum atoms. Whereas compounds 4 and 5 are examples of unsaturated metallaheteroboranes, in which the tetraborane analogues are stabilized in the coordination sphere of tantalum. One of the unique features of 3 and 5 is the presence of terminal B‐SePh. Compound 6 has similar Ta3Se6 trisbutterfly core as that of 2 with additional bridging selenide unit. All the compounds have been characterized by NMR spectroscopy, mass spectrometry, IR spectroscopy and single‐crystal X‐ray diffraction studies. [ABSTRACT FROM AUTHOR]

Treatment of a dirhodium analogue of pentaborane(9), [(Cp*Rh)2B3H7] (nido‐1; Cp* = η5‐C5Me5), with [Fe2(CO)9] at room temperature led to the formation of [(Cp*Rh)2Fe(CO)3(µ‐CO)B3H2Cl] (2) and the metal‐rich metallaborane [(Cp*Rh)2Fe(CO)3Fe(CO)2(µ‐CO)2B2H2] (3). When the same reaction was carried out at moderate temperature, two metal‐rich metallaboranes, [(Cp*Rh)3Fe(CO)2(µ3‐CO)2B2HX] 4 (X = H) and 5 (X = Cl), and a heterometallic µ9‐boride cluster, [(Cp*Rh)3(RhCO)3Fe(CO)3(µ‐CO)3B3H2] (6), were obtained. Compounds 4 and 5 can be viewed as cubane clusters with 62 cluster valence electrons (cves) and five metal–metal bonds. In another reaction, the treatment of nido‐1 with [Mn2(CO)10] yielded the heterometallic µ9‐boride cluster [(Cp*Rh)3Rh(CO)2{Mn(CO)3}2B4H3] (7). The cluster cores of both 6 and 7 are comprised of tricapped trigonal prisms containing a µ9‐B atom bonded to seven/six metals and two/three boron atoms, respectively. All the new compounds have been characterized by mass spectrometry, IR, 1H, 11B{1H}, and 13C{1H} NMR spectroscopy, and X‐ray crystallographic analysis. [ABSTRACT FROM AUTHOR]

The quadruply bridged bimetallic dithiolato complex [(Cp*W)2(µ-S)2(µ,η2-S2CH2)] (3) and the open-cage triple-decker complex [(Cp*W)2(µ-S)(µ-η4:η4-B2H2S2)] (2) have been prepared by treatment of CS2 with in situ generated [(Cp*W)2(B2H6)2] (1) obtained by the reaction of [Cp*WCl4] with [LiBH4·thf]. The solid-state X-ray diffraction structures of these complexes show the presence of doubly bridging η2-S2B2H2 and η2-S2CH2 ligands with a short W–W bond. While many dimolybdenum–sulfur compounds are known, examples of the tungsten–dithilato complexes are relatively few, and in this respect, the isolation of [(Cp*W)2(µ-S)2(µ,η2-S2CH2)] represents a rare example of this type. Electronic-structure analysis, on the grounds of density functional theory (DFT), together with X-ray diffraction studies, has rationalized the presence of short W–W and B–B bonds. Large HOMO–LUMO gaps have been observed for both compounds, which is consistent with their thermodynamic stability. All of the compounds have been characterized by mass spectrometry, IR spectroscopy, and 1H NMR, 11B NMR, and 13C NMR spectroscopy in solution, and the structural architectures have been unambiguously established by X-ray diffraction crystallographic analysis. [ABSTRACT FROM AUTHOR]